I'd prefer it if +X weapons and items were completely purged from the game. The biggest problem isn't even how they are boring or necessary, it is how that necessity strongly impacts both the economy of the game and the flexibility with which people can choose their level of magic in their own games. The linear progression of +X bonuses is the primary reason that there are magic items of varying power levels. This leads to a constant treadmill of magic item upgrades, and a system where gold is directly equivalent to character power and must be strictly regulated. This, in turn, makes it much more difficult to use gold as a valuable roleplaying tool (for things like bribes, building castles, running businesses, etc). Removing +X items cleans up this whole mess and gives players and DMs a lot more flexibility with magic items and wealth.
Also, they're boring. Really boring. Horrendously boring. In fact, the +X naming convention is downright ridiculous-sounding.
I also don't like the "newbie DM" argument. +X magic items cause a lot of troubles regarding careful allotment of wealth and items in order to maintain balance. They are deceptively powerful, far more so than many other bonus types. They also fail to be memorable, and don't provide the interesting stories that many other magical effects do. As such, it would probably be a bad idea for new DMs to give out a lot of +X items without thought. It would also be easier for a any DM to hand out items if there were no +X items around, so the negatives outweigh the positives here.
If people absolutely had to keep this scared cow around for sheer nostalgia's sake, I'd accept the removal of any +X bonus to hit rates or raw defense. Those are the bonuses that tend to mess everything up. Bonuses to damage tend to be fine. Also, I'd prefer it if the +5 in a "Flaming Sword +5" referred to the quality of the Flaming bonus, rather than a totally separate bonus. I'd still rather not see tiered magic items effects, though...