It took a while, but last year's aging DHs are finally latching on, albeit mostly to minor league/make good deals. I was going to do some digging into the why of the Guerrero signing, but Fangraphs' Eno Sarris beat me to the punch with a great article that's worth your time if you haven't read it already. To reiterate what Sarris already said, it's a nifty signing by the Blue Jays, but Vlad's Roto value is likely to be limited as a part-time bat against left-handed pitchers. You're also going to be clogging up your DH slot. That doesn't make Vlad worthless - and you should add him now in leagues where you can add minor leaguers - but don't bid more than $10-15....and even that might be a stretch.
I wouldn't even waste a reserve slot on Podsednik at this point. He hasn't played in the Majors since 2010 (yes, I'm aware he was hurt most of last year), has done poorly in the minors this year, and is 36 years old. Yes, given the Red Sox myriad problems in the outfield, Pods might get the call, go on a well-timed hot streak, and steal gobs of bases for the Sox and for your Rotisserie team. It's more likely that he'll just provide organizational depth in AAA and disappoint you. Don't let yourself be disappointed by Scott Podsednik. Life is way too short.
Banuelos' overall numbers look pretty pedestrian (particularly his K/9) so it seems unlikely that the Yankees would call him up any time soon. However, that's mostly the product of two poor starts early in the season where Banuelos was limited due to injury. His last three starts have been solid, and while I still don't see a potential ace based on three starts, it does increase the odds that the Yankees might call him up mid-year if there's a need. If you're in a league with a deep reserve list, he's fine to add as a spec play.
Scott Van Slyke
Van Slyke was already called up, but we neglected to write him up last week so here he is. He was primarily called up by the Dodgers to bolster their bench, but with Matt Kemp out it's not unfathomable that Van Slyke could see some playing time in the outfield. He mauled the Southern League last year, but he was old for the level at 24. However, it's possible that the Dodgers do give him a chance (he is starting tonight). Van Slyke is a long shot to ever make it as a regular, but he's probably made it further than one might have expected based on his early professional struggles and he could surprise given a sustained opportunity.
The Orioles traded Bell in April after a dismal start and it seemed like his chances to be a viable Major Leaguer were finished. He seems to have found new life in the Diamondbacks system, and while some of this is PCL-driven, you can't completely attribute it to that. Bell looked like a mess in Baltimore and I'm not sure if his issues as a hitter have been remedied, but Bell could get a shot in Arizona given the lack of options on the big club right now. Ryan Roberts and given way to some degree to Cody Ransom, and neither one of these guys can be considered an obstacle if Bell stays hot.
I am a big Gyorko believer, but I have to admit that his numbers in Double-A going back to last year don't scream future superstar. The Padres certainly could call up Gyorko if Chase Headley gets traded, but it's also possible that the Pads just leave him in AA or promote him to AAA later in the year. I don't think we'll see Gyorko this year until September unless he goes nuts and forces the issue.