I can't help but think they may live to regret this. Suzuki have a long long standing history of racing, BSB, and a reasonable period of time supporting road racing (albeit with a gap in the 90s). BMW have very little history of fully committed racing, I can't help but think they'll dip in for 2 - 3 good years, win what they need to win and clear off.
Suzuki may not be making the best bikes, but for the long game I'd probably prefer to stick with them. That said, I know nothing of the commercial arrangements involved, that could change everything!