Start my identifying which of the database files have the heaviest IO load and the highest delays on them. The answer to your question comes from the data. If a file has high read or write stalls, then it may be worth considering moving to a separate IO path, it may not be your log files though.
Gail Shaw
Microsoft Certified Master: SQL Server, MVP, M.Sc (Comp Sci)
SQL In The Wild: Discussions on DB performance with occasional diversions into recoverability