I would decline it, but that's just because I'm not completely sold on Pedro's health, and I'm really against getting rid of Piazza in any circumstance. Someone else's opinion might be more useful to you, but I thought I'd let you know how I feel.
Some joker in my league offerred me Mark Prior and Brad Ausmus for Mike Piazza, one day after picking up Prior. Yeah right... if I was *that* desperate for Prior, I woulda dropped Shawn Estes for him three days ago.
I like this trade for you however my one caveat would be giving up Urbina. It seems like you have a fairly powerful lineup with Glaus, Jeter, a resurgent Floyd, and a remarkable rookie in Kearns. Lieberthal is no Piazza, but if he puts up numbers he's capable of (i.e. numbers comparable to his pre-injury All-Star days), then your loss will be minimal.
I think your pitching staff could use a No. 1 starter in Pedro. It looks kind of thin. You definitely need the help Pedro can give you, but be careful it doesn't come at the expense of punting your saves category.
My advice would be to accept the trade and shop one of your bench players (an underachieving Sheffield or an overachieving Batista who probably won't see much time behind Glaus) for another closer. If you could possibly squeeze a crappy closer out of this guy or get him to bite on Mesa instead or Urbina, you'd be in good shape.
EugeneStyles gets right to the bottom line: if you don't believe Pedro has a good chance of making it through the season without spending extensive time on the DL (translation: if you'll be pulling out your hair all winter if you accept the deal and he becomes injured), close the door on this and don't look back. Trust me.
If, on the other hand, you believe Pedro's fine and usually have a stoic or zen mindset when the risks you take don't work out... well, you've still got a very tough decision. I think it'sbeenawhile hit the nail on the head here: your rotation needs an ace - at the moment, you need too many breaks to go your way. If you're playing roto, I agree that you need to ensure that you get a second closer (through this trade or from another source) before you can accept this deal. If it's h2h, this probably isn't as pressing.
If this were my team, I'd accept the deal, but that decision is based more on style of play than objective reasoning. I tend to go after high-risk/high-reward players; sometimes it works, sometimes the results are catastrophic.
Still, this call is so tight that going by playing style (or instict, or whatever) may be the best way to go here. Since we can see neither into the future nor into the workings of Pedro's arm, the only objective ways to call this seem to be:
a) Where are you in the standings? If you're in the money now, or very close, I'd stay. If you're trailing, hitch your wagon to Pedro and hope he pulls you to the top. Piazza is the very best at the weakest position; Pedro can dominate a league.
b) The sp's due for call-ups relatively soon look pretty solid; there might be a gem or two among them. Impact catchers are another story: there won't be many chances to pick up an upgrade over Lieberthal, much less a Piazza-caliber stud.
Anyway, when all is said and done, I'd want Pedro as my ace and throw caution to the proverbial wind.
Hopefully, a few more opinions will be forthcoming here. I don't know if they'll make the decision any easier, though...
Obvious players to ask for would be Hatteberg (two catchers have a better chance of heating up than one), Green (doubtful, but maybe the other owner is fed up) and Miller. You might not get any of them, but asking can't hurt.
Of catchers on the wire, I like Varitek quite a bit - more than Hatteberg, actually.
I like it. Yaritek isn't star caliber, but he's solid. I like Ortiz, and I think he's improved greatly - however, if you look beyond whip and era, the number of home runs he's given up (13) is disturbing. I haven't been able to see him pitch, but that's not a good sign. If Pedro's health concerns don't bother you too much, I'd do this deal.