Switching from Tier 2 to Tier 1?

I came to the UK on Tier 2, and with the T2 sponsorship caps, I'm concerned about my firm's ability to give me a new certificate of sponsorship for an extension when my visa expires in September 2012.

I just found out that I meet the points criteria for Tier 1, so I am considering whether it would be advantageous to apply to switch before T1 closes on 5 April, even though I still have a year and a half left. It seems like the removal of the sponsorship requirement would be a big help, but it's unclear what sort of arrangements will be in place for me to extend my T1 in 2 years time.

Any thoughts are most welcome. Thanks!

The only thing that we know is that those who have Tier 1 and their next step is ILR they will be able to apply for it. They've stated there will be 'transitional arrangements' for current Tier 1 holders that need to extend but they haven't mentioned what those will be and probably won't until T1 is eliminated for new applicants.