Don, unfortunately, the problem might be both the electronics and the speakers. I'd say that B&W DMs and NAD are both considered warm, full sounding and Rotel and the B&W CMs both tend to be more lean and detailed sounding. If you like your old NAD amp with the CM7s, then I'd suggest keeping the CM7s and the Rotel preamp and just buying a NAD 272 power amp. They come up on audiogon all the time for like $300. The 272 is totally warm and full sounding.
You have probably already played with speaker position, but if you haven't, it's worth spending time moving the speakers arournd. Closer to a corner for more bass, etc... Room acoustics can make quite a bit of difference. If the room has lots of hard surfaces, like hardwood floors and windows, this can really affect the sound. This is probably not your problem though since you were happy with the old equipment.
I will say that your post is not new. It's very common for people to upgrade from a system they are happy with and end up less happy. Especially when you change everything like you did. The same thing happened to me. It took me a few more changes until I was really happy again.
If you do end up considering a speaker change, the good news is that CM7s will sell great. I sold mine on ebay because B&W appeals to the masses, not just the audio snobs. Also, if you go the speaker route, consider Dynaudio. I love the brand's full warm sound. Good luck...