As the manufacturer
teams will essentially consist of two teams in the future (the total number being conveniently 12, to achieve an even division by 2 for BMW, Renault, Honda, Toyota, Ferrari-Fiat and McLaren to have two teams each, starting in 2008 and lasting at least for as long as the homologation does), there is bound to be movement in which manufacturer works with whom. Currently the equation isn't easy, as RBR and STR are bundled together.
The issue is explored by grandprix.com here, so I won't go into it in detail: http://www.grandprix.com/ns/ns19156.html ... But in short, they suggest that all the pieces of the grand scheme are about to fall into place "just in time" as Todt Jr. and his partners are expressing interest in acquiring STR and thus shaping it, and not Spyker, as the Ferrari "B-Team". Thus the F1 "superteam lineup" would look like this:
Renault - RBR
Ferrari - ART (ex STR)
McLaren - Prodrive
Toyota - Williams
Honda - Super Aguri
BMW - Spyker (currently the shakiest proposition, but it may well end up being a forced marriage)
What the grandprix.com article doesn't yet mention (and I've only seen scant information about this) is that Ferrari has decided to operate a driver development program of their own, just like Renault and McLaren have done. Schumacher would have the role of talent scout (and inspirator-general, no doubt) while Nicolas Todt would take care of the practicalities through ART's GP2 and F3 team.
It would suit them very well, then, that young drivers could be brought all the way to F1 by ART, lending credence to grandprix.com's speculations. I might be proven wrong of course, wouldn't be the first, but hey, sometimes you put two and two together - even if it's F1 - and end up getting four. In this case, four car teams (in anything but name) in F1.