Wireless -> Not a disadvantage really, if it was Microsoft would have done something about it now wouldn't they?
HDD -> User replaceable but + cost over doing your own is an excellent tradeoff.
Cost for online? -> Advantage, one of the reasons why Microsoft can outsell the PS3 at present by pricing the console lower IMO.
No blu tooth? Not significant market.
No Blu Ray? No point in copying Sony here, if people want it they buy a standalone or a PS3, Not really a disadvantage.
Reliability? Perhaps not so much, but its the perception of reliability which effects the market -> See GM for referrence.
Brand Name? Disadvantage, probably can fold reliability perception into this. Its not called Playstation X or whatever is probably its biggest disadvantage.
There -> Brand name is the biggest disadvantage.