Mr. Teapot
First Post
With that in mind, and to make things more interesting/complicated, check out Divine Power, somewhere around pages 15-17. (see attachment).
That text box clearly establishes that the game intends for you to be able to worship multiple gods. "There's no reason why your character must champion only a single deity".
Which makes sense, since D&D is a polytheistic setting.
It's not like worshipping multiple gods will give you huge mechanical benefits or anything. It gives you access to a handful more feats, Channel Divinities, utility powers, and paragon paths. But not many, and you still have the same number of feats/powers/etc as everyone else.
On the other hand, serving multiple gods can make for interesting roleplaying potential. Beginning to worship a new god says something about your character and his priorities.