Force 10 seems to be a relatively small company so we shouldn't expect SP to move much.

The only financial information I found on their website concerns the markets they are in. It sounds like they expect the markets they serve to reach ~ $12 billion by 2012. No mention of the percentage of the market that they will capture.

"Since its founding in 1999, Force10 has developed an extensive portfolio of Ethernet switch/routers, multiservice transport platforms, cell-site aggregators, converged access devices and security products."

From the product statement above I'd say they are in a market with significant competition.