Should projectiles in UT2004 fly faster? Maybe. In UT3? Highly doubt it. UT2004's whole dynamic is based on the dodge-jump, which is going to be removed for UT3. It made the maps huge (look at Goliath, FFS), which consequently made hitscan overpowering and projectiles underpowered because you're quite often not very close to your opponent. Perhaps having some acceleration on the rockets in UT2004 would alleviate some of this problem. Or maybe adding your current momentum to the rockets' would fix the problem, because like bri said, there's really no reason to play aggressively in this game. It's all about power-up control and hanging back and wailing on people with hitscan unless you're around the power-ups, in which case projectiles can actually help. I play aggressively all the time, and I get owned because of it. At a distance I get hit with shock beams left and right, then when I try to move in, I get comboed. Nowhere in the transaction are projectiles involved in my death most of the time. People say that hitscan doesn't rule this game, and I don't believe that for a second. If you suck at hitscan, you're bound to not be a competitive player. I suck at hitscan, so I play the role of the crazy guy who dodges like a monkey on speed and flings projectiles everywhere, and on servers where skilled players troll, I get completely owned every time.
Anyway, I don't see projectile speed being an issue in UT3 because it's supposed to be more close-quarters.