To my limited knowledge there isn't a plan to update Merc:2000. I enjoyed that spin-off as well.
When the T20 Twilight is released it will be a very simple matter to run a Merc setting. The PHB has plenty of info on vehicles and computers. Between Twilight and the PHB there will a pretty extensive weapon list. There is enough headline news around the globe to spin a fun and exciting campaign. (Did you know: According to a popular supermarket tabloid, Jesus Christ is alive and well and living in Argentina?) hehe...
So, if you like the T20 system, creating a near future setting will be a breeze.
