We can all jump in here and say that Neil is a whinge, that every one knows that Apple will do whatever it does when it suits them.... etc.
But.
Neil makes some valid points about planning in his industry. Most pro users at this level are inured to all the hype (smoke & mirrors nonsense) that a lot of tech companies may pedal. They just need to be able to buy quality equipment. Yes you could buy whats there, but he is right where the peripheral costs are enormous in his line of work, and, if Apple do something radical and shift sidewise to Thunderbolt (I really don't think they will though and drop other IO and standards at the same time) It would be a major headache.
The other argument of "just shift to another platform" if you are not happy is also disingenuous. Again cost in terms of software and time lost with a new learning curve. All headache territory.
Perhaps Apple needs its environment of hype and secrecy. I agree it is nice to have all the surprises and the success of the iPhone/iPad/iOS has been good for Apple, but in the quieter corners where serious work is done Apple should take a more conservative approach, release speed bumps with those chips that Neill referred to and give some indications of where they are going with the Pro line it would more good than bad.
If Apple think that Mac Pro is waste of their resources, then they should just say so and get out of the business. The way they are behaving it is becoming a self fulfilling prophecy. Pretending that highly specd, highly priced iMacs will cut the mustered doesn't wash with people who know their stuff.
There you go. Feel free to criticise my rant