This all seems quite silly.
Of course there are settings in a modern game that might use up more than 2GB of memory on the graphics card, but why does that matter so long as your card is balanced?
It is worrying that folks are using this info as a reason to buy 3 or 4 Gb instead of 2. Not that there are that many identical cards with double the ram for fun.
For instance, have a look at the
Guru3D BF4 performance review. First observe the 1600*1200 results and note the relative standing of the GTX770 and the 7970. This is a setting they claim consumes 1400MB of the buffer. The two cards are exactly tied.
Now look at the 4K results, the cards are again exactly tied. There is no benefit to the extra ram in this case. There are many many reasons to favor a 770 or a 280x, but frame buffer unless you plan to crossfire/sli at 4K is not one of them.
Now certainly if you could magically double the speed of the 770 it might bottleneck out on the 2GB of ram, such as 770 SLI, which is easily observed by the tanking of the 690 at 4k. But that is the ONLY card currently for sale where it is bottlenecked by the RAM at an otherwise playable setting.
Sorry for rambling but it bothers me when people (and even reviewers do it) make statements like "this card isn't future proof with only 2GB of ram". The statement is correct without the extra information, the card is not future proof, in year or so it will be too slow and you will have to reduce settings. There are exceptions in niche user requirements (SLI/crossfire for extreme resolution use in the few and far between cases where 2 cheap cards are a far better buy than a single high end one) where a card really isn't suitable for what you want to do because of its ram but these have no bearing on the modest midrange/low high end cards that more often than not see 2GB of ram. Moving forward all cards are going to be shipping with more ram, and likely ram they can make use of. Those 2GB cards we own now are going to feel slow then too, but because they can't keep up with modern titles of the day, not because they are limited in frame buffer.
If Nvidia or AMD start releasing 2GB and 4GB versions of lower end cards they are doing it to make money because big numbers sell cards, not to make a better card. This debate has been going on since the dawn of GPUs. The cards we usually see with only 2GB today simply aren't fast enough to make use of any more than that unless you plan to SLI and play on a $800+ display setup in which case budget conscious GPUs are not targeted at your demographic.