However, the WP8 source code is very different from WP7 so it will not be compatible with most "legacy" WP7 hardware. Apps developed specifically for WP8 functionality will not work on WP7 phones without some significant changes. Interestingly, WP8 appears to be designed for very long-term life - the code can support up to 64-core CPUs! (wonder what battery life is like on a 64core phone!?!?!)
My LG WP7.5 phone is the best 'smart phone' my family has owned to date - and that experience includes iPhone3, the next-to-latest Symbian phones, and two different (and very capable) Blackberrys. I'll give WP8 a chance to 'mature' a bit (and my current contract to expire) ... then I'm definitely going to get a WP8 phone.