The Lindens have recently announced a new preview of the SLim client, free for download. First you need to download a normal, special prepared, fully blown SL viewer, then you need to download the SLim viewer, too. Both are no leightweight downloads at the moment, so it wonders how "slim" SLim is going to be in the near future.
Dazzle looks quite blue, when you use it, but aside that it's still the old Lindenlab viewer, all the same menus and such, nothing new in it. Yet.
That's the difference with the OnRez Viewer. When it became public available, it had some innovations in it like the in-built webbrowser, the renovated search and others. OnRez itself was innovative, Dazzle on its own is just a new skin for the client, nothing more.
But what the client really needs is a rearrangement and rethinking of some menus, interfaces and much more, which hasn't happened in Dazzle - yet. So in that point Dazzle is simple disappointing at the moment.
The nice folks over at IBM Developerworks have started a series about Second Life. The first article of it is about how to compile your own client, the pitfalls and how to achieve the goal, since it's not so trivial to do.
Quite worth a read, better than the wiki page over at Lindenlabs and I am looking forward to the next articles of this series!