I do not know about Slacker, but Pandora should run fine.
The real question is does this fix the data streaming error that effects Pandora, Slacker, Vlingo, Twitterberry, VZNavigator or not. Somehow think only a new radio will actually fix this problem. For a lot (most?) people if you run these apps long enough, they will have connection problems with their servers. Big deal for me as these are some of my most used apps.