Not enough of a difference for most people to notice. Blu Ray also can't play regular DVD's so your current collection would be useless on the Blu Ray machine
Yes. In my opinion. A dual layer Blueray holds 50gb while the HD only holds 30gb. They are also experimenting with a quad layer which would hold 100gb. The more storage space, the more extras they can put on a single DVD. Plus there is more room for higher resolution, when such equipment becomes available.
The battle rages and it looks like consumers will have to face a dual format much like the dash R and plus R DVDs.
Samsung & LG already offer dual format machines and others will follow. This probably means both formats will survive.
Both use interactive menus but differences are – Blu-Ray capacity is 50Gb and HD-DVD is 30Gb. HD-DVD is region free while Blu-Ray is divided into three regions. (Figures Sony will try to stick it to the consumer) A disadvantage to HD-DVD is they are not all hard coated as are the Blu-Ray. HD-DVDs scratch as easily as regular DVDs while the Blu-Ray are more scratch resistant.