I think rumours of Voyager coming to DVD first (in all regions) was because Paramount Europe really wanted to release Voyager first, on the account of the VHS sales for Voyager being the strongest of all the series in Europe. I believe for sometime an official release was actually timetabled and...
There's rumours of a European release soon, and despite what people say, there's often "no smoke without fire", especially when an Paramount employee apparently started the latest rumours: See Enterprise on DVD in the Regional forum.