I just purchased the XPH and am planning to use it in conjuction with one or more one-shot adventures. For starters, I'm going to be running the Dark Sun adventure from last month's Dungeon. Then depending on how well that goes, we may try another adventure or two using that setting, but it won't be anything long duration like a real campaign. If Dungeon publishes more Dark Sun adventures, I'll likely consider running those in the same way.
Depending on how psionics works out, I will consider it for any future campaigns, but I will not modify either of my 2 existing campaigns to add them in at this time. Hence, the one-shot, non-campaign style adventures are my best bet for trying this out.