You might be surprised at how much of a difference super-scaling can make, though I do think AMD will have missed an opportunity to add a few customers if they did, in fact, not add HDMI 2.0 (as nearly useless as this will be in a year or two, though... its adoption rate is poor and it has known problems.).
However, I thoroughly confused as to why you would use an incredibly expensive TV to tide you over until a 4k projector is 'out' when they already are out... okay, so, you can buy a decent car for one (
http://www.bality.info/index.php?route=product/product&product_id=4&feed_id=79540&feed_name=madis). Hah.. it uses DisplayPort
Anyway, I'm confused why your stop-gap measure would be to buy an expensive 4K TV rather than try out some super-scaling first. The difference from VHS to DVD was pretty big. The difference from DVD to BluRay was there, but less noticeable. The difference between 1080p and 4k isn't particularly great. The lack of native content (not an issue with games, of course), performance, and product maturity really makes 4K home theater/gaming setups less than worthwhile.
I'd suggest putting your money into some AMD stock ( :whiste::hmm::|:hmm::'eek: ) and waiting for technology to advance. At which point in time, judging by the 4k projectors on the market and in development (which I only slightly follow), DisplayPort will be what you want. HDMI 2.0 will be too limiting (though it would be better to have a card with it, rather than one without it, objectively speaking).