While id Software never promised such a pack, its potential existence became substantially more blurred after the following piece of unpromising news was delivered by id's programming maestro John Carmack via Twitter.
our first test of a higher res page file didn't help much, because most source textures didn't actually have any more detail.
Basically, if the detail isn't there, upping the resolution of the textures won't help.
It's possible id might do another pass to up their detail levels, but given the time and cost of producing new assets and the fact the game's already had its main sales run, the studio's more likely to offer a rocket-powered unicorn as DLC than go down this path.
On a positive note, another tweet from Carmack mentions the next PC patch will include bicubic upsampling to "alleviate the blurry textures". Upsampling can only take you so far, however.