HTC One was recently announced and the smartphone has HTC Sense 5.0 with Android 4.1.2. The update that is now expected is Android 4.2.2, but no change in the Sense version. There are some interesting changes though:
*the battery level is shown in percentage
*extended quick settings have been inserted
*if you press home button for long, it converts into menu
According to the sources, there might be some changes in the app drawer as well. The info relating to when the update will be released, is still not clear. The HTC Sense 5.1 does not seem plausible in the near future. Get more about the prospective updates on HTC phones here.