I don't own a satellite radio. However, I have had an opportunity to channel surf and listen to some of the different channels, as my mom has a satellite radio in her car.
The Pulse seems to have a bit of a rock lean. So, if I could add a new channel, I would either add a Rhythmic AC channel or a "1990's to now" pop channel that is louder than the Blend but doesn't have a rock lean.
Other ideas for new channels...
A shuffle/variety hits channel.
A channel for Mexican music could be added and available on all radios too, not just some.
A "vacation" channel that doesn't seem to play songs from just one artist every other song (Jimmy Buffett).
Like other answers before mine said... an oldies channel that doesn't emphasize rock music or only songs from one decade.
A channel for Christian rock and rap.
A multilingual world music type of channel.
A Rhythmic Top 40 channel, for songs that might be too mainstream or too R&B for BPM but not R&B/urban enough for the Heat. Some songs on the pop chart may fall into this category, and yet they don't have their own channel but must share a Hits channel with the rock songs that are also on the pop chart.
A power metal channel, for the epic sounding catchy melodic metal (Dragonforce, Sonata Arctica, Nightwish, X Japan, etc).
That's all I got for now. After I submit this post and can't edit it any more, I'm sure I'll think of something even better (I've put some thought into this... always been interested in radio)!
Edit: As for talk programming... I'm not sure. I've always been more into music. I guess maybe some more international/foreign language programming. Maybe some more religious channels too... for people who are not Catholic or Evangelical/conservative Protestant.