Just after posting my Mylo review, I checked the mylo.com website and saw the first firmware upgrade is posted. The update release notes say on the site:

This utility updates the system to version 1.100 to improve and enhance mylo Personal Communicator features. Improvements include:

* Security vulnerability countermeasures
* System stability enhancements
* Internet applications interoperability improvements

My guess is since people started to tinker with Qtopia and the OS to run with home brew software (similar to PSP scenario), Sony started to release patches. I have a deja vu 🙂

You can get the update at Sony Support Pages

UPDATE
According to post on myloforums.net, the firmware closes the FTP port 4242, used by people to modify the system to run their code. So BEWARE, if you are planning to use such code, you may want to skip this