...why not save a few quid and run a big iMac?
It makes sense. When you consider how many people are using external storage anyway with existing Mac Pro's despite having internal bays. Having internal bays is actually pretty limiting. With the number of Thunderbolt 2 ports on the new Mac Pro it will be far more expandable than the existing machines and the iMac. I would hazard a guess that the power draw savings of the new model would be worth getting over the old Mac Pro too!
Let's not also forget that what we saw at the Apple event was a sneak peak. The full specs, features and abilities have not yet been released. Of course we all know that the price will make it prohibitive for many anyway.
But seem to have no interest regards people who have software and equipment down the line to support them with updates.
It is just when you hit a certain age group and have invested in new software and equipment a few years back and you see all this new stuff coming out.
In what regard do the new macs not have "SD Inputs"?