In a statement provided to recombu by HTC, they give the following clarification for this move -
“HTC Sense brings a variety of new software enhancements to HTC One, some of which utilize the latest hardware innovations, meaning not all functionality can be introduced to older HTC Devices. With that said, we are looking to bring a Sense 4 software update that includes as many of the enhancements as possible to a variety of our new devices.“
To put that into perspective, Sense 4.0 is designed to run on the Qualcomm S4 processor and not the S3, which is what the Sensation runs on. It makes ‘sense’ that HTC would only want the true Sense 4.0 UI experience on newer devices rather than updating older phones. Regardless if it is hardware limitations or not, it is all about selling the latest and greatest.
Those of you that were hoping to see Sense 4.0 land on your Sensation along with ICS will be slightly disappointed. While Sense 3.6 is still an improvement, you might be better off picking up Nova Launcher after the update to clean things up a bit.