History repeating
Actually, the original IBM PC was a hasty reply to Jobs' and Wozniak's garage built computer, offering an alternative to the then mainframe-dumb terminal norm. With an original time to market of 1 year (subsequently reduced to 6 months), IBM's engineers had little choice but to use off the shelf components - bar the BOIS which was later reversed engineered by Compaq, creating the PC compatible/clone market.
It's worth noting the position on those earlier players in the market today - Apple have a limited (and IMHO fairly niche) share of the PC market, IBM's PC wing was sold off to Lenovo (enjoying a similarly small share), while Compaq enjoyed a much larger until being taken over/merged with HP.
The eventual winner in the tablet market will be whoever can offer the best features and value for money as the device evolves from being a niche (want one but don't know what for) purchase to being a everyday/commodity purchase like the PC of today. This winner may be Apple, Google, MS, or even the $100 7" Apad sitting on my bedside locker running Android and apps such as Amazon Kindle.
Personally, I don't see Apple winning here long-term. Imitation cost less than innovation and the late arrivals can piggyback on the lessons learned by the early adopters. Dell ring a bell?