Ok, first of all lets set things straight -
When the game initially came in to development (by a newbie german development team called 'Deadly Electronics') back in 2004/05 it was originally called 'Virtual Rides.' Quite an extensive amount of rides and features (inc. in-game people) were included and various pictures and videos were released. At the time, the game showed a huge amount of potential.
In middle of 2006 it appeared that the game was practically 90% finished and was due to be released that same year. However, the developers were not satisfied with the dated graphics/look of the game, so late 2006 they decided to team up with VIS (creators of No Limits) and work along side them. This meant the game engine and graphics from No Limits would be implemented in to Virtual Rides, hence the re-name to 'No Limits Virtual Rides.'
Deadly Electronics are now responsible for the designing and modelling, and VIS will be dealing the programming and publishing side.
The title change has nothing to with 'popularity' and niether because they are the same franchise (as stated earlier, they are not.) Its simply because Deadly Electronics have teamed up with the creators of No Limits, so the titles of both projects have been merged together.
With regards to release date, that is the million dollar question. The developers stated the game would DEFINITELY be released back in 2006, then it changed to 'the fourth quarter of 2007', and now it has been pushed back again with no hint of release date.
One thing I can guarentee you, I seriously doubt it will be released anytime soon. As of March 22nd 2008 the developers stated the title of the game has now been reverted back to 'Virtual Rides' due to the heavy amount of requests VIS have received from people asking about the current status of the game.
Virtual Rides is now the working title, which may not neccessarily be the title for the final release.
If I had to estimate a release date, I'd say at least Oct 2008 (Though more likely Dec 2008)
Hope that is all cleared up!!
Jared
(PS. Check out http://nlvr.siteboard.org for more info on NLVR. The developers often visit the website and respond to many questions asked. Scroll to the bottom for the English Section.)