I think it's safe to say that based on the rapidly rising technology curve you'll find some really compelling options that'll best your existing set. To make a direct comparison re: your B&W's vs a new pair will be tough unless you bring your electronics with you to the new speaker demo (or they give you a trial period at home) you'll never really know if the improvement is solely in the speaker section or comprised of all the parts. I'd push for a trial period at home because not only will there be differing electronics at the store you're also demoing in a completely different room than you have at home.
I just bought a new pair of Klipsch La Scala that I have paired with an MA12000 and absolutely love them.
Good luck!