What kind of "server side" application? As a systems developer many of my applications would be more suited to Go. The biggest problem with Haskell's lazy evaluation system in real world analyses is that performance is unpredictable. While I would strongly consider using Haskell for an academic publication (e.g., my master's thesis), I would be more cautious about using it in a systems capacity. Then again, my assumption for most of HN is that we're not talking about systems development, it's just that Go is directly targeted at systems development.