Intel states this because if they can promote the ultrabook line they'll sell more CPUs.tl;dr: Intel says Ultrabooks are better than MacBook Air, but the Air is an "ultrabook" — running the same Intel chips — and is basically what defined the category to begin with.
For all intents and purposes the hardware is going to be similar to Apple's. Some makers will produce a great laptop, some will cut corners. The distinguishing factor is the OS. Given the marketshare that apple has, its in Intel's best interest to promote this new classification of laptops.
Will they be very different then the MBA, probably not, will they run as well as the MBA - probably and will do so for less $$ (generally speaking) - other then Sony who seems to want to charge a premium for their products.