whether they discontinue or not, and i don't think they will, i will probably discontinue being a mac pro user and go hackintosh when i upgrade from my 08, because:
since i bought my machine apples margins have increased somewhat distastefully in the mac pro line
compared to other platforms, features of value to a pro user are distastefully omitted [blue-ray, esata, prob usb3 in the next revision, sata3, pci expansion options etc]
and the fact that apple seems to be trailing so far behind everyone else to implement tech these days that i'll probably just get sick of waiting for whats coming when i am ready to buy again.
i think i got good value for money with my 08, but as a final cut user i'm pretty bitter that 3 years on there is still no pro software that uses those 8 cores to their potential, i'm pretty amazed that the 2 machines since then are running usb2 and firewire 800 as their fastest native interface when e-sata and now usb3 are around- and yes i know i can get a expansion cards for those but really i shouldn't have to, and with only 4 lanes if i do then i'm basically out of room to add anything that i might actually need to put in there..
as it stands these machines are getting very long in the tooth, sure they get new processors every year but without software written to optimise what % of users really cares/notices the difference. i care more that it takes me 10 hours to transfer TB+ drives back and forth by freakin usb 2 or firewire, that there are 4 drive bays instead of 6, that i run out of room for cards.
there has been 0 innovation for too long on this machine, aside from processorsits pretty much still a 5 year old g5 tower. i think this year we'll see that change or else most would consider it DOA for serious work, or they may drop it instead if they wanted to be really lame.
At the end of the day, haven't been impressed for a long time with apple basically coasting along doing as little as possible for pro's. i'll probably never leave OSX as an operating system, no time soon anyway, but i am motivated to spend my money elsewhere when it comes to building my next machine. i'm sure it will be a pain in the arse going hackintosh, i'm sure eventually there will be a mac pro that does what i want it too. but when and at what cost? i'll save my money.. put it towards migrating over to avid media composer and pro tools, lightroom, nuke and storm, and whoever else decided to innovate and do things better and refresh their product faster