This is a good step in the right direction for the PlayBook, however only some developers are able to take this step. Beta Zone has sent out an email to some developers saying that, soon there will be an updated PlayBook OS for download. OS 1.0.6 will only be available for selected developers as it is not 100% ready for even regular Beta Zone download.
The email reads:
On behalf of Research In Motion®, we are pleased to tell you about an exclusive Preview Program focused on providing developers a chance to test their applications on BlackBerry Tablet OS v1.0.6.
The goal of this program is to ensure that your AIR 2.7 and Flash 10.3 applications are optimized and ready for the BlackBerry Tablet OS v1.0.6 release. Please read this entire notice, as it contains key information about your participation in this program.
This program is only available to a select group of BlackBerry PlayBook developers; as such we are very interested in hearing your comments and experiences.
The email contains no features list, change log or any hints as to what is new or different. Only that it is coming and to be on the lookout.