And Chris Evans posted a pic of the Top Gear crew at a table waiting for Matt and Chris Harris was there, so he's still involved as well. It looks like the new format has more presenters...

Well thats funny, I thought it was announced she was a host, I guess something changed?

From the BBC
Eddie Jordan and Sabine Schmitz join Top Gear line-up - BBC News

Meet your new top gear presenters (full line up)

Meet your new Top Gear presenters! | Top Gear

That's a lot of people... Eddie Jordan is a bit of a whack job too... I guess this will not follow the old 3 guys format !

My guess is that they are going to have 3-4 per show, and as the cream rises to the top, they'll do more and more and the others will do less and less.

Only a revolving two to four will be in most of the segments (other than perhaps the studio stuff with the audience). All six will shift through various films, races and contests. (I highly doubt they'd take all six to Africa (for example) but you never know.