I'd like to buy a 6630.. but i have a question:
anyone knows if software written for 7650 and other series 60 symbian 7 phones is compatible with 6630 (series 60 symbian 8)?
They should, in general, as long as the developer(s) have used APIs (Application Programming Interfaces) as documented in the published Series 60 SDKs (Software Development Kits).
Your mileage may vary, as Americans sometimes say.