The folks over at www.Blackberryos.com came across OS Version 188.8.131.52 for the tour, over the last few days some screen shot had been floating around with a tour running that OS but now you can pick it up for your self at the following MegaUpload link : http://www.megaupload.com/?d=Y1572GME.
Looks like the original leak came from BBHybrids. Kudos Matt!
Let us know in the comments area what you find with this release, bugs and fixes.
Seems like the CDMA devices have seen a few OS upgrades & leaks which leaves me wondering where are the upgrades for the other devices such as the bold, 8900 has not seen an upgrade for 4.6.1 since a few months now, so hopefully that means official OS 5.0 is next?
Note: Do this upgrade at your own risk because it may render your device unusable if you are not familiar with OS upgrades, this is a Beta OS and not an official release.