DAVIDSAN  I have the same machine, and yes it is 32 bits. And I am running SL too.

I believe a more comprehensive list about the new features can be found here:

http://communities.vmware.com/docs/DOC-10957

Support for OpenGL in XP, for example, is new. And it says, it is optimized for SL (32 and 64 bits).  
(Version 3.0)

DAVIDSAN  All Intel Macs can upgrade to Snow Leopard, and they will see improvements. Disk space, faster startup and shutdown, Cocoa Finder and many more. It is true 64 bits processor will benefit more, but 32 bit Intel will see benefits also.  
(Version 3.0)

DAVIDSAN  It is not compatible with Snow Leopard! Too bad!  
(Version 2.0)

DAVIDSAN  The problem seems to be hotmail.

Try turning on the Develop(er) menu in Safari's prefs. Then at the Hotmail login page (or once you've logged in) change the User Agent (what Safari reports itself as to the web server) under that menu to one of the Firefox variants. Firefox 2.0.0.20-Mac worked for me as I was having a similar problem that started this week.

From this...

http://discussions.apple.com/thread.jspa?messageID=9054383  
(Version 4.0b1)

DAVIDSAN  I am having lots of troubles with my hotmail account and Safari 4 Beta. In fact, none of the links to see messages work and I only get errors on the console.

However, all the other pages I have tried work flawlessly.  
(Version 4.0b1)

DAVIDSAN  I do not know what is happening with this app.

It crashes a lot on MacBook Pro 17 inch 2.16 with 10.5.6. I mean a lot!  
(Version 1.2.1)

DAVIDSAN  This update solved all the issues I had with 1.1.2 about High definition video. No more frames dropped!

However, I keep clicking on the Load External Subtitles to deactivate them, but when I reload the preferences pane is again checked. It seems like a little bug.

Any way, great job!  
(Version 1.1.3)

DAVIDSAN  Something very strange is happening with this version of Perian.

When I watch content on my computer with Perian installed, version 1.1.2, 1080p movies loses frames. I have been watching the Star Trek trailer 2 with and without Perian 1.1.2 installed.

When Perian is installed I lose frames. Perian not installed, all trailer is played perfectly.

My computer is a Macbook Pro 17 inch 2.16 Core Duo (No Core 2 Duo) 2Gb RAM.

So I guess, something is wrong with Perian that is using its own H264 codec instead of Apple's.  
(Version 1.1.2)