I was poking around the web a couple of nights ago and came across a product seemingly specifically made to BMW spec. Motul's 6100 LF-01 0w-30, as the name implies, is made specifically to meet BMW's new LongLife-01 motor oil requirements. Their LeMans 15w-60 might even be suitable as a substitute for the 10w-60 Castrol RS/TWS S54-spec oil.
Though I'm a Mobil1 user, I'd be interested in finding out how much this stuff costs, or even if its available in the US. I know of a Motul dealer locally but their website doesn't list the LF-01.