That site also has this article comparing Sage to Myth from a 'long time' MythTV user. For people in UK (and possibly Europe) much of the cost discussions are not applicable as the EPG data available for free over the air or via grabbers/scrapers.

Like Mark says, if they get the Sage extenders (or something similar) working as super simple mini frontends then that would be even better. While a MythTV frontend for Windows would be nice, but for me it's hardly a deal-breaker given you can still stream recordings over Mythweb using the win32 player of your choice.