Over 80% of new blocks are now Version 2. Once this hits 95% any version 1 block you mine will be
rejected by the network.
An upgrade to 0.7 is necessary (or 0.8.1 when available).
Yesterday, core dev and btc guild rescued miners on an old version, but it won't happen for version 1 miners when they are churning out orphans with unspendable rewards.
Don't be among the last few heading for the exit on version 1 getting guaranteed down-time.
The percentage at the bottom of this screen is moving centre-stage in the Bitcoin show now:
http://blockorigin.pfoe.be/top.php