The gunbarrel logo is just as much Bond as a black tuxedo is, as far as I'm concerned. It is high time the gunbarrel is placed in the proper position, that being the beginning. For two simple reasons I believe: One being that the ending of Skyfall would set up the films being opened with a gunbarrel perfectly as now, a male M resides in a familiar office setting and both a new Moneypenny and Q have been established. Secondly, if the producers wanted to leave the past in the past, they wouldn't have taken these steps to establish these characters as the films were going along just fine without them.
Therefore, as far as I'm concerned it is just a matter of time (much like seeing a new Q and Moneypenny) before the gunbarrel sequence returns to the beginning of the films.
Saying flatly that the gunbarrel sequence was a part of the old 007 series is hogwash. Much like Bond, the gunbarrel will return... and Bond 24 would be a perfect opportunity to return such an element in my opinion, due to how Bond's story has progressed of course.