Are these another air shock ?

The reason I ask is that I am thinking of upgrading my Vanillas, but fox seemed to have moved towards making the vanillas a longer travel fork and as a result not suited to 5" rear travel xc bikes

140mm is approximately 5.5" inches, so they almost match the rear end travel.
Yes the Talas is air sprung, it stands for Travel Adjustable Linear Air Spring (I think (geektastic)) 🙂

you can shim down the vanillas (and drop a-c at the same time) – Mojo sell all sorts of spaecers of different lengths.

Depends on the age of the Vanillas old ones pre 07 from you can change travel spacers around. 140mm ones 07 – 09 are not adjustable. Unless you can get a cut down spring, which will also affect the spring rate. The 2010 FIT equipped ones aren't adjustable either.
Vanilla 32mm are no more in 2011 as well!