President Obama is probably BlackBerry's last famous user... for now.
The White House is currently testing Samsung and LG Android devices, and Obama may be able to land one before his term ends. Though, it may be months from now before he's able to make the change official. If the government and its top man drop BlackBerry from their orders, it may definitely be one of the final nails in the coffin for the struggling company (the government has been a long time customer.)
Obama's phone, whether it's BlackBerry or Android, will be heavily modified, and will be much more secure than the phones you and I use. The BlackBerry the President owns now only allows him to contact 10 people... so maybe it's better ours aren't like that.