Imvu has been trying to upgrade for eons, the new imvu desktop is a step in the right direction even if its hated by most. Its wayyy smoother, it however has its drawbacks and many of them. But thats the reason imvu is stuck where it is. Too many people are hating the change. Imvu even had a game version where we could walk around WITH our avis, just like in second life, it was short lived due to ppl stuck in imvu's current state. But it was the ABSOLUTE FUNNEST THING EVER! I miss it!
I forget the engine they were using, but it was web based, which was sadly unfortunate, and probably contributed to its downfall. I still miss it though. However back to the topic, yes they wish to move forward, and are currently trying to do so without the welcome of the angry public. Ppl leaving etc. I believe when it happens, IF it happens the complaining public will be back.
Also making a living on SL now is nearly impossible for a noob, so I hear. Less people are using it and coming to imvu. In SL you need a decent spot to sell from, and most of the best ones cost $$$. Not to mention you have to pay per month to even get access to the good stuff + pay for the land itself which is, you guess it more $$$. I'm not sure what happened there but its a cash dump now it seems. By the time you pay all that vs. the amount you make off of things, it doesn't add up well. At lease on imvu you are able to at least break even as a noob. I tossed over $1000 down the drain b4 I gave up. I was all gun ho thinking "well you gotta spend money to make money" yeaaa, in the time that takes you could make 10 stores on imvu.