VS has been preparing for Adriana to take over that lead spot for most likely 2 years or more. The 08 VSFS was a big indicator, she got the fantasy bra, opened the show, closed the segment, wore the fantasy bra, and besides Heidi got the biggest opening. If you look around most of the flagship stores, her images are everywhere much more than any other girl. She opens the show more than any other current angel, and now has worn the bra twice as well. They had Adriana do most of the launches/talk shows and etc with Heidi in the last few years, so VS knows what they are doing.
VS has always went in order of seniority, never anything else. With that being said, and along with all the press, media and other obvious signs, Adriana being lead angel is obvious. Heidi has wanted to leave for a while now, but VS was holding onto her until they were ready to let her go (most people don't know this) and it was in order to get a new lead Angel ready, because lets face it two years ago Adriana wasn't ready then. She is now, and she's been doing well all year.
Adriana's career is going to be going into overdrive with VS, she's about where heidi was in 2002, in everything, doing every launch, getting all the big honors and etc. Adriana is leading the Christmas commercial, going back and taking over swim (heck it's her 5th day shooting swim today), she'll be the headliner of this show, she's the main face of their beauty line and everything. It's very clear VS has made her the lead, and they are going to use it in every advantage they have. Eventually she'll only make 1-3 appearances like Heidi did toward the end, but that's several years away.
I think anyone hoping, wanting or crossing there fingers that any other Angel has taken that lead position can just laugh it off at this point.
With that being said, I think that is what she's focusing on. She hasn't worked this much for VS in years, now that she's the HBIC she's going to work a whole lot more. My guess is after the busiest part of the year for VS dies down a little bit (December and on) She'll return to more editorials, and HF and etc. Remember if anything VS will be having her in editorials more often if not to push their own product.