I'm a fan too, been through several! II,3,3c,5,5MX still got the 5MX in daily use, although I tend to need the screen fixed about every 2 years.
There is nothing else in the market that is as usable simpply because there is nothing else with a decent keyboard.
I heard - from a man who sold them the Bluetooth chips. That just before the line was canned Psion had a Bluetooth enabled version ready to ship - they were crushed apparently!
Mind you this:
www.oqo.com looks pretty good, even if I do think the keyboard looks dubious.