I think, given the "Premium" tag is being thrown around more, and applies to a track now, that I'm actually more concerned with a solid description of what that entails, even more so than a solid release date. If a "Premium" track means night/day and/or weather, cool; if "Premium" means "this was made specially for GT5", while non-Premiums are essentially lifted from GT4 and given a slight visual makeover, I'll be disappointed. Same applies to the cars; if "Premium" is a nod to damage, I'm still going to wonder why they'd only have around 2/10 of the lineup accepting more serious damage, given the 5 years they've had to work on this. That and I imagine online races between Premium and non-Premium could end up badly.
Ideally, if this is the case, I would hope that after the game is released, we'd get DLC on a regular basis slowly putting everything to the same level. Advertising extensive damage but not having it across the board is a bit misleading.