My gut feeling is that you're being overly worried.
Chaosium seem to manage a pretty decent publishing schedule with CoC, plus they have the option of publishing monographs on certain products, which mitigates their risk and (presumably) time to market. I'm not sure whether all the announced products are going to be full-colour, monograph, or what, but personally I'm cheered that Chaosium are showing such an obvious will to support their new product. The one thing I think that is clear is that BRP will live or die based upon the support material - sourcebooks, settings, and scenarios - that comes out immediately after the rulesbook release. You can't afford not to be planning for that.
Remember too that Chaosium haven't committed to releasing all these products all at once on the same day or anything - it's their production pipeline, and they'll doubtless see the light of day "when they're good and ready", or something like.
Having said all that, I'm hoping we'll see an increased amount of fan activity and fan publications following the rules release - the RPG market these days seems always hungry for regular activity and updates to generate and maintain interest levels, so fanzines, websites, and so on would be a great way to keep the buzz going between releases.
Cheers,
Sarah