I am glad we have a few statisticians on this thread so, let me recap for the others:
1. Both formats have a positive trend which does not show that either format is flagging, and this is not looking like the UMD trend!
2. Avg rank trend slop is higher for BD, so it does show that there is more purchase taking place for that format.
3. However, the slope of new titles trend and released titles trend is higher or greater than the sales rank trend slope.
4. This shows that HD DVD will need fewer titles to match the sales rank of BD - given other things stay as they are.
My point is that the current trends on dvdwars by no means shows weakening of HD DVD, while showing adoption for BD. The recent slew of new titles IMHO has more to do with the sales ranking than the PS3. The PS3 impact is there, but it's the relative lack of HD DVD titles that is effecting the rankings.....should not be surprising.
dvdwars is a valuable source for analysis....