Future of BESX

[fire6]

My work, small municipality, is using BESX. It works well for the company owned phones and works for the BYOBB. What does the future look like with the new BES/Mobile Fusion. All the webcast and articles state that Mobile Fusion will work with the updated BES 5. No where I have read is BESX mentioned. Will it be a system that if still used will be left in the dust? My IT does allow activesync devices on our network now. I can see the advantages of Mobile Fusion to allow the governing of all these devices in one place, but does that mean that our organization will have to go back to the old BES cals for every old BB device just to accommodate the new activesync devices. In a small local government it would be a big deal to replace all city owned phones just for the new system. And the IT dept. has been enjoying, along with the BYOBB people, the free service. As a current owner of the BB playbook looking forward to OS 2.0 how will I be effected by my work not adopting the Mobile Fusion.
I know we might now know the answers for awhile but any input is appreciated.