Here's a copy-paste from HTC SEA website:

Update – HTC Legend Firmware Over The Air (FOTA) update
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.  After installing the update, 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 1.31.707.3. Note：We recommend using a free Wi-Fi hotspot or an unlimited data plan to apply this update. If not, standard data connection charges may apply. For any questions, please contact us at http://www.htc.com/www/CA_Hotline.aspx

seems like a minor update: v1.31.707.3

I wonder if it'll work for rooted phones?