We’re in the process of finalizing a quotation module for Magento called Cart2Quote. It offers the store owner the possibility of capturing requests for quote as well as regular orders. The store owner can then send quotations based on those requests, and final offers can be purchased through a regular payment process.
Such functionality is highly sought after in the B2B market and tailors Magento a little more toward this very promising market segment.
Signing up for the beta at email@example.com ensures a 50% discount on the final module when it goes on sale. (Provided you are an active beta tester of course.)