I am so glad SQL Server finally caught up to Oracle on making itself more ANSI-99 compliant in the area of "row based window frames". I always theorized MS intentionally did this to get customers to try SSAS. This, of course, is a baseless theory of mine that I could never prove. Does anyone know the REAL answer as to why it took so long?
I would also love to one day see a Modenar* regarding performance diffferences between native window framing in SQL 2012 vs pre-2012, more imaginative (sorta) solutions. As The Kimball Group once said "just because your RDBMS is ANSI compliant does NOT mean the RDBMS performs those operations well"!
*A Modenar is a passionate teaching to the SQL Server community on set-based data processing and all the tools available to do so in a tireless effort to rid the world of intra-database RBAR.