It's sad to see this point glossed over so often. Obviously we haven't seen the film yet, but given the connotations of the marketing material we've been presented with, and what we (think) we know, this seems fairly clear to me.
The tragic irony of the whole situation is that by the end of TDK, just as Bruce has finally realized how much
he needs Batman, he has also come to find how much Gotham
doesn't need Batman; or rather, how bad Batman actually is for Gotham. Now, this isn't necessarily true, but it stems from Bruce's warped, often extreme thinking.
"Did I bring this upon her? I was meant to inspire good. Not madness, not death."
With Rachel's death and Harvey's fall, thanks to the influence of a demon spawn of the Batman persona (the Joker), Bruce sees just how destructive and poisonous Batman can be. As with Batman Begins, where he is on the extremely optimistic end of the spectrum, here he succumbs to another extreme: Batman, for all the good that the guise has brought, has been much more of a negative than a positive.
Thus, at a time when Bruce personally rediscovers his need for the mask, he also realizes what that mask has been responsible for. So as much as it may pain him, and as much as petty crime and such might still exist in Gotham, Batman's presence is a greater threat (in Bruce's mind), and he must therefore stay away. And, as noted by Nolan and company, superficially, Bruce made the right choice for Gotham, but with Bane's revolution, we'll ultimately learn what a mistake it really was.
Again, we find the beautiful irony of it all: TDK is initially all about Bruce wanting to hang up the cape and cowl, and yet when he finally finds himself requiring that double life, Gotham reaches a point where Batman must be excised in order for harmony to prevail. Giving up Batman to maintain the city's social order is the ultimate act of altruism on Bruce's part, and I find that pretty compelling.
That's why the eight years thing, as it stands now, doesn't really bother me. Thematically, and from a character-based perspective, it adds a new layer of depth to Bruce. Moreover, it further shows just how devoted he is to Gotham, giving up the very thing he craves for the sake the city. The fact that we get hermit Bruce for EIGHT YEARS (!) as a result of giving up Batman should be more than enough to illustrate to anyone just how much Bruce actually needed Batman.
Clearly, the man isn't very happy at the beginning of TDKR...
Now, I can totally understand why fans of the "everlasting Batman" would dislike the eight years thing, but I think it's a shame that I don't see others bringing up what you said more often. To me, it just makes everything that much more interesting, and in particular, Bruce's relationship with Batman, and how important it actually is.
) but whatever.
