Sounds like a really nice, practical cartridge. Actually, the .338-308 has been quite popular in Canada for a couple of decades in M99 Savages and M88 Winchesters, so it is not an unknown quantity.
Yeah, it would very useful. Whether such a round is marketable today, when 3,000+ fps sells, is another thing entirely. I'm guessing that it will sell to those who realize its usefulness and slowly fade away, like its cousin, the .358 Winchester (another fabulously useful elk-banger).
I can imagine a Remington 700 Ti in .338 Federal. Oh yeah.
Steve