The second birth of Gandalf Stormcrow
 

I am unsure whether there is a quote somewhere that can support my theory, but I feel that Tolkien may have considered it important to ensure that while Gandalf was housed in the body of a man, then he must, while in Middle-Earth abide somewhat by the rules that governs all men, that death finds each of us, Istari included. Even Gandalf cannot cheat death, in actual fact he cannot cheat the separation of the fea and hroa while he occupies this house. The divine intervention comes only after the death itself takes place, which of course must occur for Gandalf cannot avoid the natural separation as it takes its course following the long battle with the Balrog of Moria. He has to die like any man, even though he is Maia.

His departure from beyond the realms of Arda strangely enough seems exactly like the journey mens spirit would make as they pass from death into life to the place Eru has set aside for them. The difference being, Gandalf is sent back. It seems to have religious connoctations to it, yet somehow I wonder if Tolkien in doing this makes Gandalf more like Man than Maia, to glimpse the death of Man in order for Gandalf to understand why he must return and complete his task on behalf of the race of Men?!

Another intriguing topic, Ancalagon'sFire! (Btw, is there any specific way you'd prefer your name to be shortened? It takes so long to type!) You might like to have a look at this thread for some controversial opinions on what exactly happened to the Istari when they died. Personally, I still hold with the idea that Gandalf experienced something at least very similar to the fate of Men; at the time there were some good arguments to the contrary (i.e. that he was merely 'uncloaked';) and returned to Aman to be sent back by the Valar), but I'd be interested in seeing another angle on the question.

If it could be reduced to Ancalagon, I would be chuffed:) Otherwise, 'Anc' is fine.