Right now at the earnings call, RBC asked how exactly did BlackBerry plan on pulling in back customers onto BES12 and get them to upgrade or join onto the BlackBerry Enterprise. They responded with the fact that Enterprises are still pretty much based on the legacy devices and that was a big factor hindering their migration. As such, with BES 12, they will be supporting back the legacy devices and they are looking to push it for availability even earlier. Planned initially for the November timeframe, they are now pushing forward for the October release.
Hopefully this would help to stem and make the flow to BES 10 solutions increase. This is one large window of opportunity and BlackBerry should indeed really work to get this out as soon as possible.