HTC has been officially announced a list of android phone which will get ICS update last week but HTC Desire HD is not included in the list. I’m not surprised if Desire HD will not get official OS upgrade maybe since it 2010-released phone, although from the hardware aspect is still capable to run ICS smoothly since this smartphone meet minimum requirements (768 MB RAM, 1 GHz. and Adreano GPU).
If HTC fails to deliver update, our last hope is update it with custom ROMs. After Google released ICS source code few days ago, now developers from xda-developers working together to build Android 4.0 ROM for Desire HD. Previously the work with SDK port and now they working with ICS source code. The previous SDK port is successfully boots, calls, sms, data (in 2G network) and you could expect more when the ROM is ported from ICS source code. If you prefer to use CM9 from CyanogenMod Team you have to wait for about 2 months before try out the ROMs. If you interesting to update it with custom ROM you can try to root your phone now and gaining S-OFF first on HTC Desire HD. We will post an update once a stable ROM is roll out.