There really aren't many fixes that the Angels need; their rotation is pretty solid, and they are one of the two or three teams that doesn't need bullpen help. Their main trading chip at this point is Shea Hillenbrand, who was designated for assignment today. Obviously, they'll get very little in return for him, but the Yankees are interested in the rather mediocre first baseman. The Angels have apparently had discussions about Mark Teixeira and Adam Dunn, for some reason, even though they don't really need a first baseman. I don't really see a whole lot of improvements they can make in their lineup, though if they can pick up a DH cheap they might look into that.
Seattle: Wait a minute - Seattle? What the hell are they doing here? Shouldn't they be at the bottom of this list? The Mariners are a very surprising 42-33 this year, although they're still 5 games back of the Angels and a couple games out of the wild card. But don't let their record fool you - their run differential is that of a .500 team, so they're lucky to be where they are. In addition, most of their players are playing better than they should, so they're not likely to stay at anything close to this pace. Their hitters have been fairly solid up and down the lineup, which is surprising because they don't really have that many good hitters. They view themselves as contenders, and I guess when you're 9 games above .500, you've got to take a shot at the playoffs, but I wouldn't be too optimistic if I were a Mariner fan. Felix Hernandez has been very up-and-down, and Jarrod Washburn and Miguel Batista have been good starters, but they could certainly use another pitcher or two. Jeff Weaver has pitched like...well, Jeff Weaver, and his ERA is an ugly 7.71. J.J. Putz has been absolutely dominant as the M's closer, and the rest of their bullpen has been surprisingly solid.
The Mariners could certainly use some help in their rotation, and possibly their lineup, but they don't really have anybody that other teams covet. They might try to trade away Jose Guillen, as they have a solid replacement waiting in the wings in Adam Jones, but I'm not sure they could get anything for him. It would make sense to try to trade one of their overachieving relievers in a market that is starved for pitching, but I don't know who exactly would be interested in them, either. They've looked into Mark Buehrle, but I can't imagine they'd be able to come up with an enticing package of prospects for him.
Oakland: The A's have a better run differential than the Mariners, but are just two games above .500 as of today. They definately still have a shot at the playoffs, but they've got a lot of teams to catch if they are to get into the postseason. They've been hit hard by injuries; Rich Harden has ace stuff, but can't stay healthy. But the biggest problem for the A's is an anemic offense. Nick Swisher's .858 OPS has been fine, and Dan Johnson is starting to hit pretty well, as we expected, but the rest of their hitters are just mediocre. Bobby Crosby has a .284 OBP, and Jason Kendall is officially the worst hitter with a starting job in the major leagues - his .513 OPS (.259 SLG!!!) can attest to that. The other half of the game has not been a problem for Oakland - they've allowed the second-fewest runs in the AL (one more than Boston). In a just world, Dan Haren would be your All-Star game starter (we should know on Sunday whether or not that actually happens), with a 1.91 ERA and a WHIP under 1. All of their other regular starting pitchers have ERAs under 4. Their bullpen hasn't been spectacular, but it's been solid. Without any offense, though, they'll probably remain around .500.
The A's just recently cut outfielder Milton Bradley, for reasons not fully explained, and they dealt him to the Padres for reliever Andrew Brown, who should help them some, although they don't really need more pitching. MLB Trade Rumors has also speculated that they might trade Joe Kennedy, who is a free agent after this year, but that's probably unlikely. I don't see Billy Beane making any major moves this year; the A's will probably contend next year if they can pick up a little bit of offense thru free agency, and they don't really have anybody that other teams really covet.
Texas: Can Sammy Sosa just go away now? He's gotten his OBP up to .311 now, but that still isn't really helping the Rangers much. He's still contributing some through his .475 slugging percentage, but the Rangers aren't winning now or anytime in the near future; they need to start giving at-bats to their younger players. (The same can be said for the state's other team; Craig Biggio's been even worse than Sosa this year, and the Astros had some hope of contending at some point this season, though that's all but faded.) Mark Teixeira has been the lone bright spot for Texas, giving them a .959 OPS; Ian Kinsler's given them decent production from second base, but Michael Young isn't having nearly the year he was projected to, and they really haven't gotten a whole lot of offense from anywhere else. The bigger problem is their pitching; they've given up the second-most runs in all of baseball (only Tampa Bay's been worse), and they don't really have anybody on their team who has been underachieving - their pitchers just aren't any good. One would like to think that Brandon McCarthy (acquired from the White Sox this winter) at least has potential, but his ERA is 5.90 so far, and that's the lowest of any Rangers starter. Their bullpen's been okay, but not all that great.
Who do the Rangers move? Anybody that someone else wants. Eric Gagne and Akinori Otsuka have been pretty good coming out of the bullpen, and a number of teams (especially the Indians, who have some history of trading with Texas) have interest in both pitchers. Mark Teixeira is the best hitter on the market, but a deal for a hitter of his ability midseason seems somewhat unlikely (see Alfonso Soriano last year); they'll probably have more luck shopping him during the offseason. The Dodgers have interest in Teix, and they have the prospects to get a deal done, but they won't want to give up most of their young players.