Apparently - this is the deal with Ultrapeer:
When you connect to an Ultrapeer, it drops all of your other connections to reduce congestion and to assist your uploads/downloads by giving them extra bandwidth.
When you search the network, your search request goes to the ultrapeer and the ultrapeer does your searching for you, thus shielding you from the bulk of the traffic from the network (= good!)
The ultrapeer knows most of the files on your computer and only delivers search messages to your computer if it believes you have a file of use.
Ultrapeer is not fully perfected yet, it is merely an architecture that they have put out to try and reduce traffic (= better network health = good!). More updates to Ultrapeer will come with new releases of the software.
Many Gnutella products are starting to develop in accordance with the Ultrapeer Standard.
The Ultrapeer Design can only benifit us if we use it in it's earlier stages. If we don't give it a go, it may just disappear altogether and that would be a great loss as it would deprive the network of a great protocol.

Those are the facts as I have heard - I posted them here to save you sifting the posts for answers.

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JM