Hi Terence,
You are right in many aspects, in particular when it comes to doing edits on a tablet to a photograph... Being a photographer I see no point in editing photographs on a display that will not show true colours to begin with... And in fact the fact that both Aperture and Lightroom do not support editing within colour channels (only photoshop does to my knowledge) makes them both very clumsy tools apart from two important functions: 1 sorting and previewing 2 adjusting exposure (and ONLY exposure). Aperture has a better RAW converter than Lightroom this is the only reason for using Aperture over Lightroom (OK it is user friendlier too).
The only Workflow support a tablet CAN and should provide professionally speaking is pre-sorting, ratings, colour labeling, possibly croppings. Everything else should be manioulaated on a big true colour screen and preferably within the colour channels in Hotoshop.
That means all the iPad needs to provide is: 1) an upload from you camera directly into the iPad (check) 2) a sorting, labeling and rating function.
Ironically the second function does exist -- for Lightroom .... The app is called Photosmith and works like a charm. Unfortunately Lightrooms RAW converter isn't great so then I have to export from Lightroom back to several folder mimicking my various rating and sortings and then re-import to Aperture... Yes we're in 2012! And yes we are talking of the prime product of the most highly valued Technology company called Apple
I'm going at length to explain this because a) I'm increasingly frustrated at Apple's complete misregard for real professional needs (which seems to grow exponantionally with every success they celebrate in the consumer market) and b) frustrated with the ipad - being one of my worst purchases in 2011. Not because it isn't cool, but because it is simply being artificially cut in functionality just so that Apple may sell more Macbooks.
Because the only true reason for a laptop these days is either you are constantly travelling - and I mean constantly... which few people truely are... or you're working in a remote location... Or your iPad just doesn't perform enough even for basics so that you still need to take a laptop even if you're away for just a week or two and intheory all you need is email and an app to rate and colour code the images you took, and possibly upload them to a server so that an assistant can take care of the rest - because you're too busy to be actually retouching images anyway...
I hope Tim Cook will change a few things - he does seem a bit less stubborn. I am hoping for the best because I know a few people within my circles (we're all early adopters and were proud owners of the Titanium Powerbook) who are already thinking of alternatives... Cheers