Lively is an interesting new entry into the 25 year history of room based avatar chat applications (15 if you only count the 3d ones). At the moment though, there's little to differentiate it from the rest of the top ten.

The low barrier of entry to these kind of av chat systems makes them hugely popular with the under 20s social market, which eventually often turns business and education off using them... but i digress.

It seems that at the moment Lively is pretty, but at about the level of 3d av chats from the early ninties in terms of functionality. We can see that it has the potential for user generated content, and could have better systems for privs built in at a later date. If they do this well in about a year it should approach activeworlds or vastparks level of interestingness. Even so they'd still have a way to go before reducing the gap between content creators and proper 3d game developers. Sketchup looks like a good candidate for integration there.

So the long and the short of it is don't pack your bags from SL yet. Lively has a LONG way to go before it catches up with what sl does well (if sometimes unreliably :). And before it eats SL it'll have to eat IMVU, Gaia, Kaneva, Metaplace and most of the rest of the industry first... after all, those are the virtual worlds that Lively's current model is closest to, and thus its direct competitors.

Just my two cents.