I know there are older threads on this, but I would like to bring it up again. I play electric bass guitar and live in NYC, which means subways and such. The only really nice super-protective guitar bags I know of were from Incase, which aren't made anymore. I guess they made too much money on iPod/iPhone accessories. I actually have an Incase bass bag and it is indeed unbelievably-designed. But there's one, IMO, huge flaw in it that made it very frustrating using it in NYC. It sits very high. I'm only about 5'7" and the top is over 12" higher than my head. This means that I have to duck in the subway, often. The top gets hit a lot, but thankfully the Incase is very well-protected.
So I know that these threads go back years, but any chance of something like this happening? For what it's worth, I have lots of ideas of how a bag like this could be great. There are lots of forums for guitar and bass that would probably be into this. I participate on talkbass.com for example.