You are most likely looking at July or worse for 20nm, though they might release a 28nm (who knows) then move it to 20nm later by xmas for a refresh. I hope they don't do this as there is nothing more to get from 28nm as Hawaii has shown. You have to up power by increasing size of the die at this point, which in turn adds noise/watts. NV is already above AMD and this is pretty much purely due to size of the die (it's likely a better gpu, but a lot of the perf and lower heat comes from a huge die that just gets more work done per mhz). IF AMD grew the die to 530mm they could drop the temps to 83 out of the box also and get basically the same perf as 780ti while doing it (100mm=10-20% perf or so right?). But you'd all complain about the price...LOL. Considering NV is already producing pretty much the max sized die TSMC can produce on 28nm, what else can you do except raise the mhz, watts, heat?
Considering both AMD/NV seem to be making huge dies now, it will take a die shrink for either side to do anything meaningful. AMD used to make smaller ones, which allowed cheaper pricing; hence the enlarged hawaii comes in at 400/550 and probably still won't make any GPU money (the game bundle being cut-down shows this is more expensive-well duh it's larger). I don't expect a price cut soon on the new AMD gpus even after NV lowered theirs. AMD can't be making much even after lowering the bundle and lowering before xmas surely would equal losses.
The only reason AMD made any money last Q was PRE-console chip orders to get the launches of both consoles out the door. It remains to be seen if they will keep ordering tons after xmas. Sales up to xmas I guess will dictate those numbers. If there is a massive drop-off up to xmas then they will do the same as apple etc, and reduce orders due to products not selling like they though. You can imagine the cancelled orders on chips running wiiu which hasn't cracked 5million yet (has it cracked 3.5mil?). They are under 50% of what they expected so clearly someone had to say OK, lets stop ordering new ones made since our shelves, warehouses etc are already at full tilt and we need to sell some crap before ordering more chips, memory, cases etc...It affects everyone making something in the wiiu box.
It doesn't help AMD numbers with 1/3 of the PS4's coming DOA on amazon alone and I'm sure a LOT of xbox360 owners have RROD firmly in their minds now seeing PS4 issues out of the game (granted probably sabotage, but users don't care, it's BROKE no matter who did it). Do you risk buying your kids a DOA xmas gift or just buy a new gpu, phone, tablet etc which aren't famous (yet?) for their failures? Any bad info hurts sales at this point, and that leads to no devs, no games, no BUYERS:
http://arstechnica.com/gaming/2013/10/the-wii-u-death-spiral-and-how-nintendo-can-reverse-it/
There's a rundown of what happens when hardware/software sales suck. Even a price cut probably won't help much as a quick look at metacritic shows only 37 games above a score of 75. Most of those are on other platforms with far better graphics, so why would I buy one? NV can afford to take less per gpu if needed to get a product out the door, but seeing AMD so weak, I doubt they'll go EARLY with 20nm and take risks. There is no need as AMD can't even afford a risk and must go late I'd think.
To be honest, I think we'll see LARGE die products (gpus from amd/nv) late in the year as they want to test 20nm with smaller chips that aren't wasting such huge space on failed dies (considering both company's profits, I'd think you need to MILK this current cow quite a bit longer also). It's expensive to test new processes on the largest chips being produced by anyone. GPU's are the largest dies of anything outside of Intel 15 core Xeons (which are 541mm- Ivy Bridge-EX-15).
You get the point. Large dies will come last most likely after experience is gained from 20nm socs etc. I doubt the next gpus will be any easier to make than current gk110b or Hawaii so assume their replacements will be later. IE, they should be able to sell this HOF model for 6-9 months. AMD doesn't even have an AIB with better fans/heatsink announced yet right? OR did I miss an announcement? Still all REF designs. All of the new cards have plenty of time to sell (probably more like 9-10 months for both sides).