A quick view of the standings will show who will most likely be Sellers at the trade deadline.
The Blue Jays have been traders, but roster builders. The Red Sox are traders as contenders, but are pretenders this season. The Royals, Brewers and Diamondbacks are on the fence. The Phillies may be surprise sellers because of their lost season. The Twins are sellers in rebuild mode around a core of aging and injured veterans. The A's are perennial sellers looking more at the new stadium than roster moves. The Mariners are catch and release sellers (with teams like the Cubs making waiver claims off their roster). The Astros could be reluctant sellers because they have little to trade. The Rockies are probable sellers. The Padres as team is literally still for sale. And the Cubs are in full fire sale, garage sale mode.
The teams that are most likely sellers are Twins, A's, Mariners, Phils, Astros, Rockies and Cubs. Each team's likely trade bait (current salaries included in millions):
The Twins could have a pitching swap meet. Starters Pavano (9), Baker (6.5), Liriano (5.5), reliever Capps (4.5) and possibly utility-catcher Doumit (3.5).
The A's could unload relievers Balfour (4) and Fuentes (5) but more likely Inge (5.5) or Suzuki (5).
The Mariners could possibly salary dump Figgins (9.5), Guiterrez (5.8), League (5) and Vargas (4.8).
The Rockies have already shopped starter Guthrie (8.2) and have no long term need for Giambi (1).
The Astros also could dump salary in Carlos Lee (19), reliever Myers (12) or starter Wandy Rodriguez (10.5), a consistent lefty on a bad team.
The Phils could either hold pat for next season or play mega-dealer. Hamels (15) is heading for free agency so he is a rent-a-player candidate. Veterans Polanco (6) and Wiggington (4) could command interest for a team rounding up a strong bench.
As set forth earlier in this blog, the Cubs block includes Dempster, Garza, LaHair, Soriano and Barney. So the Cubs are probably in the middle of the pack as buyers evaluate the available talent pool.
If you look at all the trade candidates above, it is not really a strong talent market. Either the players are expensive or on the downside of their careers. But that is partially negated by the moment; some teams need to win now and will overlook those concerns.