In all honesty this is probably a good thing; better than you probably realize right now. The truth is, sometimes things have to get worse before they get better.
The fact of the matter is, on many long encounters, hunters have lots of mana and OOM problems. This is mostly because aspect of the viper is terrible as it doesn't provide enough mana regen, and you have to give up hawk to use it. This problem is compounded by the fact that hawk is the by far the best raid aspect to use since the best raid DPS build relies on the imp hawk talent.
This doesn't do BM hunters any good if they're forced into Viper aspect just to have mediocre mana regen (which is still far short of where it needs to be to stay competitively DPSing with a mana-intensive shot rotation).
The Old Fix:
The way around this before was to FD/Drink back up to full, and resume using a mana-intensive shot rotation. This way hunters could at least stay somewhat competitive in raid DPS.
Now that the unintentional band-aid of FD/Drink to regen mana during boss fights (which is just a bad mechanic as is anyways) has been lifted and the underlying problem revealed, it will probably become readily apparent to Blizzard in the near-future as to:
A) How much hunters were relying on this poor mans mechanic of mana regen (in addition to mana pots)
B) The fact that hunters in general need better ways of mana conservation and/or regeneration.
This also hurts marks builds more than BM, since marks shot rotations are much more mana-intensive than BM shot rotations, which consist mostly of steady-auto.
This is really up to Blizzard. There have already been countless threads and great discussions on the mana issues that hunters have. Part of the problem lies in aspects, another part of the problem is in the talents, and this even extends into bad itemization, unfortunately. Hunters have to pay a higher ilvl tax than rogues do, even though rogues have near the exact same stat point distribution on items.
Hunters have to sacrifice other stats on their gear for INT, yet for only a few points of INT. In addition, INT does not help hunters as much as it should, with as much as they rely on it, in addition to how little INT they receive due to itemization. This ties directly into talent problems, as INT needs to be scaled more into AP or some other statistical equivalent so that it holds more weight when stat point distribution comes into play.
In addition, Aspect of the Viper still does not provide enough of a mana regeneration component to warrant use of it over hawk (again, especially for BM raid builds which are again, the highest Raid DPS spec). This also ties back directly into itemization, as AotV depends heavily on how much INT you have.