Personally, I like the newer look of the Core Book covers. True, it has been emulated now by many other RPG publishers (notably FFG) but I always thought it to be a really neat idea. Maybe they will do a "black leatherbound" look for the new PHB cover...
Also, what the heck is all this crap about "traditional looking weapons and armor?" This is High Fantasy D&D, not historical reenactment! Give me the oddball armors and weapons, spikes, buckles, patches, pouches, protrusions and all! In fact, I want the guys who designed the various armors from the LotR movies to help with the concept art. There's nothing wrong with your typical Knights in Armor ala Excalibur, but I want some out-there stuff as well. I think it's great that the designers decided to go outside the bounds of normal medieval/reniassance weaponry to include a few oddities (double weapons, mostly) and I think they should go even further; weapons with absolutely no basis in history whatsoever (which may be difficult given the sheer variety of cultures and weapons that existed on Earth)!
This is D&D, it's Fantasy. It's not Hyper-Realistic Medieval Earth Simulation. If that's what you want, then just redo the equipment lists and tell your players that armor doesn't look the way its drawn in the book. Personally, I want armor that inspires the imagination and looks different. If I wanted historically accurate armor, I'd purchase a fully illustrated medieval arms resource book from Borders or B&N.