I finally got around to updating my XM Radio activity which now reflects the current channel lineup as of July 1, 2011. The activity is part of my current XCF file which can be downloaded via the first post of this thread. Screenshots of the activity linked to below. Enjoy!

XM Radio Favorites: 01, 02
XM Radio Music: 01, 02, 03, 04, 05, 06, 07, 08, 09
XM Radio News: 01, 02, 03
XM Radio Sports: 01, 02, 03
XM Radio More: 01, 02, 03, 04
XM Radio Info: 01
XM Radio Keypad: 01

Added notes...
Originally this activity consisted of 5 separate devices (or activities as they are called in PEP v2), one for each of the categories used. This allowed for the Page Up and Page Down special actions to only page through the pages for a given category. I've since implemented ProntoScript which has allowed me to use one device instead. I'm also keeping track of the last page displayed for each category as well. When selecting a given category you are always taken to the last page displayed for that category, even if you had left the activity and returned to it later on. When intially going to the activity or leaving the activity and returning you will always start under the "Favorites" category however.