If you compare 2 Kings 2 and 3 with 2 Chron 21, it will appear that Elijah was not indeed, permanently transported to "heaven."
I read a bit about it in an article on WND (link on this page, to the right), but it was vague enough, so I looked it up. It takes a bit of fishing, but if you go by the "dates" of the kings taking over and the rebellion of Moab, etc, it is plain enough that Elijah's letter to the king was written after his trip in the whirlwind. So it would seem that he simply went away, as the prophets thought at the time.
ETA: I didn't dig far enough the first time (sorry, blushing) because it was Moab rebelled in Kings, and Edom rebelled in Chronicles (when Elijah wrote the letter); apparently this was even later than I first thought. Definitely after the whirlwind incident.