I was a big fan of the first Google Desktop search when it came out, but over time I gradually figured out that I was only using it for searching email so when I re-installed I decided to just install Lookout and not worry about Google Desktop anymore. Today Google launched a new version of Google Desktop and it has a pretty cool sidebar along with it, it is something of a mix between the now missing Longhorn sidebar and the recently acquired Konfabulator. I decided to give it a try and here is my verdict:
Pros
1) Gmail tie-in is awesome.
2) Stocks are goood, and it picked up the stocks I entered at google.com/ig.
3) Easy to move around, dock, etc.
4) Not too invasive, doesn't seem to take as much room as it actually does
5) Extensible. There is a SDK and even some level of support for VS.NET (I would love to write a couple plug-ins, but I don't know if I will be able to find the time)
6) Already some cool plug-ins available (Tasks one is very cool, so is the Adsense one)
Cons
1) Crashed on me once already, had to end-task to get it working again.
2) Still uses web search interface (but has added the quick results that MSN search has). This is good and bad, I like how it integrates with the regular google search, but I dislike the idea of having it running some sort of local web server.
I always love these things when I first install them, then over time I quit using them and eventually un-install them... so we will see if I am still using it in a couple weeks.