Is 3.5E "the system" then, and there will be no 4E? Not at all. 3.5E has displayed more problems - rocketing caster levels in relation to Holy Word, the ongoing problems with polymorph, an incomplete weapon sizing system (reach & missile weapons need better definition), and so on.
Yeah, but IMHO, what would be best is not overhauling it into 4e, but tweaking and re-tweaking.
The comparison I use is to an MMORPG. You buy the initial game, and all the while you play it, it gets little updates and tweaks -- abilities get added or subtracted, changed or manipulated, characters become different, class powers are adjusted. Mnor things -- 3.5 things.
D&D as it is today could use a patch or two. But it doesn't need a whole new game just yet.
For instance, we could use a monster system that keeps HD from monster type in line with HD from class levels, thus eliminating the awkward LA paper tiger syndrome. We could use a power system that didn't rely on character treasure to measure power.
However, that doesn't really require a 4e.
To put it in persepctive, 3e changed the way that D&D was played. AC no longer counted down. THAC0 vanished. We had a grid. Only 3 saves. More classes, and 20 levels of each for any race. This idea of one unified XP chart. That definately changed the feel of the game.
I don't think 3e needs to be changed like that. We don't need to re-write the basic "d20 + mods vs. DC" mechanic. We don't need to alter the way AC, attack bonuses, or save bonuses work. We don't need to give uo the grid, or go back to 2e multiclassing or different XP charts for different characters. We don't need to change the feel of the game -- just the implementation of certain ideas.
We can always use minor adjustments -- a revision every handful of years is probably just what the doctor ordered, and keeps the core rulebook sales brisk. I definately know I don't need a new game, though. And if I did, I have dozens of d20 or d20-compatible games to choose from right this very moment without having to invest in a completely new edition with completely new supplements.
I don't think that a problem with a single spell is enough to dictate a new edition. I would think a new edition would be DRASTIC. And drastic isn't something that I'm really interested in happening to my D&D game at the moment.