Yes this might give you another shock after the news of WhatsApp acquisition by Facebook but now you can really hide the last seen on WhatsApp though as of now this feature is available for Android only after the it was introduced for iOS users. The last seen feature which served great utility to know weather the person has read your status or not also turned into nightmare for some but finally everyone can just relax & use that feature as with last seen WhatsApp is also serving the function to hide your DP & Status too.
At first place i should mention that it is not officlay available on play store yet so to use that feature you have to download the WhatsApp Apk file from WhatsApps Official site. Do note that before unintalling the WhatsApp you should make a backup of your chats & then uninstall the WhatsApp so that you can use your chat backup with the new WhatsApp version. The feature is not yet available on the play store means it is still in testing & WhatsApp can pull the plug on it any time they feel feature is not up to their expectations. So if you want to use the feature download the WhatsApp apk file as soon as you can.
The feature lets you toggle the status any time you want unlike the iOS users where they have to wait for 24 hrs to make the changes effective. As of now it only provides the function to hide it from strangers or from everyone so right now you cant set it for only selected users well for that you can just block them.
Well it will prove to be quite a move if the feature can make it onto the official version as most of the users were demanding something like this. So Download the new version from WhatsApp Site & play a havoc with other contacts.