Not sure there will be a "winner".
Like current DVD - and + standards, that everyone asked the same question of, eventually, and probably from the outset the new HD-DVD, BD players / recorders will support both formats in one machine.
So I would imagine media cost and availability will determine which format becomes more popular.
And long before there is an eventual winner as such that one format is the dominant there will be a new bigger and better format/s come along to take their place.
The only loser will be the media / tech companies themselves, as the average consumer will become confused by multiple formats, and may well decide not to upgrade from standard DVD, which most people seem to find has enough quality to suit them as it stands.
Just my two peneth. R.