This is a deal that is difficult to say "Steal" or "bust."
The Dodgers sought bullpen help after they sent Schmoll and Sanchez to the Mets, and there was a match between them and the D'Rays: the Rays sought pitching prospects and the Dodgers have a ton of 'em. The Rays, on the other hand, now understand that no one will give them top talent (aka Hanley Ramirez) for Danys Baez, with the new management trying to make a move.
First off, the Dodgers get two relievers: Lance Carter and Danys Baez. I am woefully unimpressed with Lance Carter. His K/9 is pretty abysmal, and, based on his innings/games ratio and Prospectus' LEVERAGE stat (.78), it appears that Lance Carter was a mop-up man, of sorts, for the D'Rays. Quite frankly, the Devil Ray bullpen was nothing to write home about, as they say. That's not a good position to be in. Carter is filler and is probably a downgrade from Schmoll.
Baez, on the other hand, brings in that glorious Proven CloserTM label that so many teams covet. He's also a pretty solid reliever, although teams who were listing him as a top target at the deadline and in the offseason are a bit blinded by the PC label. The K/9 has declined in back-to-back years, so keep an eye on that. I don't really worry about his BABIP-luck: either he's been lucky for three straight years or he's doing something to keep it down a little.
With all that said, Baez is not a stud reliever. He's a reliever who just happened to be used in a lot of save situations and managed to rack up 41 saves. He will help the Dodgers, but he's nothing too spectacular.
What about the prospects they gave up?
Edwin Jackson melted down in some ways since being a massively hyped prospect going into 2004. His last 50 innings in the bigs have seen an ERA close to 7, and he also managed to post an 8.62 ERA in AAA Las Vegas. I don't know very much about this story as far as details go, but something obviously troubled Jackson for the last two years, whether it be some injury (he was put on the DL in 2004 with a strained right forearm), something psychological, or a combination. In either case, it's tough to forget that Jackson will be 22 on Opening Day and could still manage to turn his career around and fulfill some of his promise. The D'Rays are taking that gamble and it's one that I like.
Chuck Tiffany, on the other hand, worries me. I've never seen him pitch, of course, but I find it troubling that he gave up 17 homers in 110 innings... in the Florida State League. Vero Beach supposedly is a hitter's park in the pitcher's league, but I'm still concerned. He also gave up a lot of hits, if I'm doing my off-hand estimation correctly, with that strikeout rate. He looks dangerously hittable in some ways, kinda like Yusmeiro Petit, but a level too low to be really impressive. Really, I'm being hard on Tiffany. I don't know much about prospecting; these are just my mini-impressions. An educated opinion on Tiffany can be found at John Sickels' blog. Check #6.
I'm really being a fatalist with a lot of these mini-evaluations. In reality, I think that the Devil Rays made an interesting gamble in trying to resurrect Edwin Jackson. Tiffany could pan out... he's a good prospect.
I don't necessarily like the relievers that the Dodgers got, but the farm system is a position of strength, and it's OK to work from that position of strength. The Dodgers are in win-now mode, it seems, and that's sensible: their division is terrible and they're much better than the 71-win team that was wrecked by injuries last year.
I'll give a conservative evaluation: not bad for either side, not great for either side.