I've been thinking about this a bit. Personally, I do like unlocking things, but it really is a deterrent to new players. Not only do they get waxed for the normal reasons, such as not knowing maps as well, but the players who have been playing longer also have a distinct tangible advantage. Their characters are simply superior. There really is no reason to start players out with such a disadvantage.
Besides, it's not like it takes that long to unlock everything. This system sounds like it will encourage players to do more than just run deathmatch after deathmatch.