I dont think you'll see the 4k market blossom until a REAL effort is made to actually offer 4k media...great to have a 4k projector thats upscaling 1080p media but in the end its still a 1080p image slightly sharpened nothing like a true 4k image. Basically like buying a Corvette and not having rims and wheels for it or like putting bike tires on it...just not really useful.... I could be 100% wrong but I see no value to owning a 4k projector unless I can download or go to the store and buy a 4k DVD. I'm thinking it'll catch on within the next 5 years because some TV's are slowly getting out there..I saw a 55inch at SAMS club for $5499
Everything else being equal, I could use 4K resolution now, even with only Blu Ray / HDTV, to either sit closer to the screen, or use a bigger / wider screen. So I would find 4K useful, but that's just me.