For hitters, I think the safest play is Jeremy Reed. He's a polished hitter with a great K/BB ratio. Dallas McPherson and Nick Swisher have huge upsides, but could fizzle as well. McPherson has the highest upside, but also has the highest chance of not being able of make contact and being a hurtful fantasy contributor.
For pitchers, Kazmir and Capellan are nice talents who should get good K's, but I think they'll walk their fair share and have high 4.00 ERA's. I like Gavin Floyd, but don't like his home park for him. I think Blanton will be solid as he has good control and is pitching in a pitcher's park. The other 3 I mentioned have much higher upsides though.
The people I mentioned were called up in August and later.