DailyTech had a chat with JMicron on SSD controllers, you can read it over here. Here's a bit of information about what you can expect from future JMicron SSD controllers:
Some customers have introduced high speed SSDs with JMicron's RAID controller JMB390, plus two JMF602B controllers. The target performance is 233MB/sec on sequential read and 166MB/sec on sequential write. Moving forward, JMicron is developing SSD controllers with DRAM cache and it is expected to be available in Q3 2009. That will totally solve the random read/write performance issue.