manufacturer HTC has started to release updates for some of its Windows Mobile 5 devices to Windows Mobile 6 and the TyTN (codname Hermes) is the first device to get upgraded.
The next few devices to get this upgrade is the P3300 (Artemis), the X7500 (Advantage) and finally the S620 (Excalibur), all some time later this month.
However, if you own a third party or network branded device other than Dopod, then you're out of luck, as you now have to join the HTC eClub to be able to download files and this requires that you register your device with HTC.
We'd suggest having a look around the web where you can download the new firmware from various websites.
You can read the full press release here