I have been using Google Desktop for about a week now and it is a wonderful tool to have, except for few caveats.

It works seamlessly out of box (didn't yet find out where it is storing all the indexed information) and is very useful to find information specially for people like me who loves to store information, yet don't give enough time to organize it. Google is proving to be the one stop way to access information anywhere I want, including emails. And I can reply, forward my emails from google interface (integrated with Outlook). However it doesn't allow me to delete them.

On web search it does a parallel search of my hard-disk, in addition to the web, to fetch relevant information and merges the results.

It would be wonderful if we can extend it to include all the information across a corporation.

I found that if I rename a directory, then it cannot intelligently show me the documents from the new directory. Also I have no control over:
1. Forcing Google Desktop to re-index particular contents
2. Forcing google desktop to recognize the new location

Enhacements I would like to see:
1. Ability to delete emails
2. Ability to specify cache location & size
3. Ability to specify index location & size
4. Ability to manually clear index & cache
5. Ability to specify information category and search within category
6. Authentication, for computers used by multiple people

All in all despite its easy and capability of use I have to conclude it is still very much a work in progress.