Here's my take on the Vancian/Non-Vancian rift:
Personally, I have come to greatly dislike D&D's iteration of "Vancian" casting, particularly for Wizards and Clerics. When I GM 3.x/Pathfinder games, if a player wants a "Wizard" or "Cleric," I'll often houserule that they can play a Sorc, Psion, Ardent, Runethain from Arcana Evolved, etc. instead, but not the base Wiz/Cleric. Conceptually, "memorize/forget" just doesn't jive with the way I envision magic working in most of my campaigns.
I've tried the Unearthed Arcana spellpoint system, bought the Lycean magic PDF from En Publishing, the Spellweaver variant caster, tried the "Truenaming" variant from the late 3.5 splatbook . . . basically, if there's a way to replace Vancian magic in D&D, I've looked at it.
That said, D&D is very specifically tied to its version of Vancian casting, and I think it's probably going to stay that way . . . and I'm actually okay with it, whereas in the past that would have frustrated me. It kind of is a "core trope" of D&D (even though it's easily my least favorite magic mechanic), but if I don't want Vancian casting, I'll either keep houseruling, or simply play something else.