First of all, it's a little inaccurate to categorize FFXII as a "one off project from the FFT team." Many of the staff members of XII are veterans from FFX, such as the scenario writer, and several lead graphic and programming designers. Also, the executive producer of the project last made his appearance in the series as Director for FFII.

Not only that, but I'm not sure why you claim "Matsuno & Co." have left Squeenix - Matsuno seems to be the only one gone. The composer is freelance, and he recently assisted with Revenant Wings, so I'm sure he's going to contribute to more SE projects down the road. Also, the co-director, who received a bump up to director, seems to have popped up quite alot at the conferences for the game, talking about things like "when we make a Final Fantasy..." so I'm sure we'll be hearing more things from him down the line. Then there's Ito, who worked on the majority of FF's and will undoubtedly serve on more down the line. I think you get the point.
You have a point there. But in terms of storyline the games will be very different. Matsuno had his own way of telling a story whereas Nomura's is completely different. Also the character designers are different.

Sakimoto could contribute to more FF music, but thats going to be in a long time from now. Its going to be a long, long time before FFXIV is released.

What I meant by new direction of FF, is that all the new installments seem to be very distinct from each other, as opposed to the first 9 which are in alot of ways fundamentally the same thing. Also, with FFXI and XII having very similar battle systems, it makes you wonder if this is the new direction FF is taking? Only time will tell, but I believe you are extremely mistaken for thinking that none of the contributors to XII will have any further influence on the series following XIII.
Sure there will be many contributors continuing on but it is the lead figures who influence the game the most.
FFXIII
Yoshinori Kitase (game producer)
Motomu Toriyama (game director)
Kazushige Nojima (scenario writer)
Tetsuya Nomura (character designer)
Yoaka Amano (title logo designer)
Nobuo Uematsu (theme song composer)
Masashi Hamauzu (music composer)

FFXII
Yasumi Matsuno (original concept)
Akitoshi Kawazu (executive producer)
Hiroshi Minagawa (director)
Hiroyuki Itō (design director)
Daisuke Watanabe (scenario writer)
Hitoshi Sakimoto (music composer)
Yoaka Amano (image illustrator, title logo designer)
Akihiko Yoshida (character designer)

FFvXIII
Shinji Hashimoto (game producer)
Tetsuya Nomura (game director, character designer)
Yoko Shimomura (composer)
Yoaka Amano (image illustrator, title logo designer)

So I think my point still stands.

I do agree that FFXII contributors will still have influence but expect to see a very different style game. Also, the battling system for both upcoming PS3 games will be considerably different to XII.

However, Im sure they'll keep things that FFXII did well such as sprawling environments and the like.