"In our commitment to providing you with the best user experience, we are pushing out a new firmware update to your phone. Your phone will receive a notification of this update when it is made available. Simply press OK to accept the update via a data connection such as Wi-Fi or GPRS/3G," says HTC on their support pages.
Strangely HTC doesn't actually detail what the new firmware update offers, either on their support website or via the OTA update that is being pushed to the phone, however users over at xda developers forum are saying that it is:
"Minor fixes. New radio image. New YouTube app with HQ option (with a widget that doesn't work if you're logged in to your account). New bootloader. Fixed Facebook/unknown contact issue (haven't verified this personally)."
After installing the update, which won't wipe your data, you can confirm a successful update by confirming the Software Number (From the Home Screen go to MENU> Settings> About Phone> Software information> Software number). The new software number after the update will be 1.31.405.4 on HTC Legend and 1.21.405.2 on HTC Desire.
Although the update isn't very large, HTC recommend using a free Wi-Fi hotspot or an unlimited data plan to apply this update.
We've already received the update on a HTC Legend on Vodafone in the office and itseems to be little change. Have you received your update push request yet? Let us know if you've spotted anything new.