If you go to the HTC website you will find no mention of the Inspire 4g. You cannot find it on the support page and if you do a search on their site, it will come up with one result that makes no mention of the Inspire 4g. It is like this phone never existed.
My hope, and I hate that four letter word, is that because this is the same phone as the Desire HD it will be getting the update. The reason I say this is that when you are on the Google Play Marketplace and purchase an app, you are asked what device you want to install it to and the phone comes up as the Desire HD. Also when I pair my BlueAnt Q2 headset to any of my phones it says the model of the device you connected to, mine that I have are the Inspire 4g and it says Desire HD, the Atrix 2 and it says MB865 and a crappy Blackberry Curve 8300 and it says Blackberry 8300.
Just my 2 cents.