I agree about Hudson: he remains a premier starter and is starting to heat up. He makes a great acquisition now.
Zito's numbers so far are actually very similar to what he put up last year. Will he win 20? Maybe, maybe not, but I look for him to continue pitching at his current level.
Both Zito and Hudson could use an outing or two with low pitch counts, however.
Agreed about Padilla as well.
Vazquez is indeed nasty; he was hit hard in his last two outings, but I'm not worried about him. If Montreal is serious about making a push for the pennant, he might even get some better run support.
Armas has looked awfully good lately. I don't think he's quite at Vazquez' level, but he's still a solid pickup.
Oswalt's also been getting hit pretty hard lately. His price will certainly be right now, but let's wait and see how he gets over this slump before handing out next year's Cy. That ballpark he pitches in still worries me a bit...
Perez is an absolutely amazing story. I'd love to see him continue to pitch as he has, but fatigue might start to become a factor. I think he'll be good in the second half, but not as good as he's been so far.
And I very much doubt that Santana can keep up his pace. I may be wrong, but I think he'll come down to earth fairly quickly.
Let's see, other sleepers... Benson comes to mind - I'm not sure he's back at full strength yet, but it's worth keeping an eye on. Josh Beckett has slipped from the minds of lots of fantasy owners and might actually be considered a sleeper for the second half. Nick Neugebauer's return should be interesting, too...