Gandalf the White

[Elemmírë]

A new annoying, semi-philosophical question for you to ponder! Aren't you so very lucky?

"Yes, I am white now," said Gandalf. "Indeed I am Saruman, one might almost say, Saruman as he should have been" (The Two Towers, The White Rider).

At first glance, I don't think there is anything extraordinary in this quote. Ironic, yes; especially remarkable, no.

However, on second thought, I wonder what exactly is meant by this line. How can he almost be Saruman? In essence, the two of them appear to be completely different. Saruman is a Maia of Aulë, one concerned primarily with skill. Gandalf, on the other hand, dwelt in Lórien but was taught by Nienna. To me, their backgrounds seem completely different. It is almost like saying... that Finarfin is Fëanor as he should have been...

Am I analysing this quote too much? Does it simply mean that Gandalf has been sent back to play the role that Saruman should have filled?

Or is the nature of the Maiar different and more... fluid, for lack of a better word, than I had imagined? Just what sort of transformation did Gandalf truly undergo?