Hi Vishnu,
This site is running the very latest code with recent improvements to the search. I will be explaining the new features soon via docmentation and blog posts.
However it does not meet all your requests. The search engine is only used for content not users. There is currently no way to lookup users by custom profile fields. I did implement the ability to filter search by feature so you can search only forums or blogs or whatever, but it does not yet allow searching only a specific forum or by date.
Some of those things like the ability to search specific forums or by date and more advanced user search may come in the future.
Best,
Joe