OK, here's some quick hits and crunch in the manner of Dr. D.
Brian Wilson
The Red Sox pretty much took away the whole "fear the beard" business, so what's the point?
Not really.
The real question is "is he back"?
All we know for sure is that he faced 49 batters in the regular season and then 24 more in the playoffs, and in that small amout of results, everything looked just like it did before.
Other than a slightly high BB% throughout, Wilson has shown everything you want in a late-inning guy. Lots of strikeouts, and he doesn't hurt himself: super-low HR/9; super-low ISO-against.
They will spend money somewhere, and a vet to help glue the bullpen together isn't the worst option. Wilson is obviously a risk, but the M's will have to take some risks to get their money spent this winter.
Grant Balfour
No beard, less known, kind of a journeyman, but Balfour has gotten the job done as the A's closer the last two years.
And the A's have, you know, won the West both those years. Must be nice to know what that feels like.
Balfour, however, doesn't quite bring Wilson's results. His BB% is a bit high as well (not uncommon for high-K guys), but he's been much less consistent than Wilson at avoiding homers. So I would expect more streakiness.
That being said, he'll be 36 and probably won't entail as much of a commitment as Wilson. (Wilson will be 32 and will presumably command a prime-time deal.)
There are lots of power arms bubbling up the minor-league ranks (that's something this regime has been very good at spotting and snagging), but we've also seen the potential downside of relying too heavily on those guys, no matter how good they are.
Jhonny Peralta
Peralta has met with the M's, according to the rumor mill. Drayer hinted that the M's were hoping for a two-year deal that would keep an infield spot warm for D.J. Peterson, but that's by the boards now, since Peralta is seeking a four-year pact and claims to already have a four-year offer (at $13M/year) in hand.
Would the M's still bite at a four-year deal? Well, the infield is already crowded and Peterson and Ji-Man Choi are on the way, so you'd expect Peralta to end up in the outfield at some point in a four-year period.
Is he enough of a solid bat to just sign him and worry about how the defense shakes out later? Not really, but the M's also don't want another off-season where they come up empty and have to "rely on the kids," so maybe going four years on Peralta is a fail-safe position.
He wouldn't be a thrilling add, but, as we discussed, he's a very good bet to produce middle-of-the-pack numbers, and that's not a bad thing at all.