i believe it is rape, unless you and your partner pre-planned it together while sober, or have talked about in full significance prior to the occasion, and always check after the occasion if anything was particularly displeasing or abusive, intentionally or inadvertently so.
To note, there is a clear distinction between "drunk" and "buzzed". in the event of both individuals being familiar with alcohol, and by experience can tell and function while "buzzed", one may yet be able to consent, as long as neither party pushes consumption to the limit and become truly "drunken".
in all cases, it is important to discuss this with your lover, preferably at length and before "the intended occasion," or in some cases after the first "unintended occurrence." The sexiest thing there is be communication. Without effective communication, which assuredly transcends language, but often requires it in some form, then there is no romance, and certainly no consent.
Now, that said, i, personally am shy. i have never been buzzed or had anything more than 1/3 part red wine, and i am not particular to alcohol. However, as an encourager, with a respectable, safe, and considerate, devoted significant other, i would consider it for my nerves, or his, but not without respectful discussion, first, and never with over consumption. After all, how sexy is it to remember nothing when you wake up because you were TRULY "drunken"?