chrish100,
something I could suggest is to set up an MS Search server. Even the free express edition would work well. If you wish to index the textual content inside the dwg's (text etc.) you will need to purchase the DWG iFilter you mentioned. In my experience, this iFilter did not appear to index the attribute information inside the dwg but was able to pick up on the mtext and text notes. The easiest way to make this all work is to import your DWG's into a Sharepoint list or library. If you simply want to make the files easier to find, you don't have to import them into a sharepoint list but you will not be able to associate other data with them. In this simpler scenario, you can just point to Search Server indexing to the folders/shares you have the files hosted.
You can also check out BIMworld Library manager. It is an independent product that includes the ability to manage DWG data. I have not found anything that can dig out the meta data of the files. We currently have the need for this with our Revit family library. We have actually created something internally for this.
One of the great things about the Sharepoint framework is that there is abundant information available as well as many developers that can customize it's functionality for you.
There are other worksharing/portals available in the open source world as well such as O3Spaces and Liferay.
Also, remember that Windows desktop Search can provide the ability to index content to make it much easier to find for the end users. This is available with both XP and Vista. Google desktop provides similar functionality.
