As mentioned in the DVD delay press release, the new tentative release date for the "Metropolis 2000" DVD is April 24th, 2001. The record label still wants to release the DVD and VHS simultaneously, which means the VHS will be released on April 24th as well.
CDNow is currently cancelling all pre-orders, and other online stores are expected to do the same very soon.
As soon as CDNow starts taking pre-orders again, an announcement will be posted right here and on the weekly Dream Theater newsletter. The newsletter is also used to send out press releases and news flashes, so you might want to consider subscribing, if you haven't done so already.
Pre-orders for the Region 2 DVD and the PAL video at BlackStar in the UK will not be cancelled. So if you can order from them without any problems (they offer free shipping worldwide).