In CS5, and in various documentation it doesn't appear possible to be a way to move multiple anchor points (as it is, in Photoshop). If this is the case... are you kidding me? Even Photoshop can do this.
Quite frankly, on my return to Illustrator, it's, as expected, Adobe has pulled a fast one with their suite of software. What was broken years ago is still broken today.
Photoshop needs the ability to add gradients to shapes, path brushing, symbols, ie the functionality of Illustrator needs to be placed into Photoshop.
Are you saying that if you use the direct select tool and hold down the shift key and select several anchor points you can't move them with the arrow keys?
I certainly can without any problem? It maybe that the increment that they are being moved at is smaller than you would prefer and you can change that in the Preferences.
Also unlike photoshop if you select multiple points in AI you can than drag one of them and the other selected points will move as well.
If you need more support for manipulateing path look at the Astute plug in Vectorscribe.