if it was the case , people had stopped buying all in ones, actually the popularity of all in one is increasing day by day ,its size is shrinking and more features are becoming standard,and they are becoming more reliable then standalone inkjets. dell has captured 19% all in one market in just 2-3 years , just remember that all in one cant match two separate devices e.g. an hp photosmart 7260 $99 and epson perfection 1670 photo $99 can knock down any competitive all in one upto $300 range in performance and in quality .
its just like combo drives jack of all master of none . best thing is to keep your price down so you can get most bang out of your bucks.
just check out the hp 4215,before making the final decision.
http://reviews.cnet.com/HP_OfficeJet_42 ... tml?tag=sd