Development Update (tablets and mobile) and revised release date
Development / Testing for V4 is going well but with a bit of delay, primarily because of the user experience tests I perform with tablets. I want to ensure that users browsing on an iPad can enjoy the standard theme (non-mobile) if they choose too. For this purpose a bit of experimentation and rework is required to meet this requirement.
I also tested the WYSIWYG editor capability on iOS 5 but so far the platform is not mature enough for me to support it (flaky implementation).
V4 will also have a mobile theme designed and refined for smartphones, and it will be in a separate folder under the main forum root. It is much more efficient (less download) and less error prone to move the design for small screens outside the main forum.
In conclusion, what I'd like to achieve in V4 is consistent user experience on various devices, especially by providing a full experience for tablet users.
I'd like to apologize for those who have been waiting for the release for V4. I received inquiries and business proposals by emails and PMs last couple of weeks asking me for the ETA.
Here is the revised date for V4 and a bit of Q and A: 
I am in the process of packaging V4 and transforming it into a platform that can help build online community in a more comprehensive manner. The "social scape" has changed considerably and we need a platform that provides better integration with content publishing, community building and social networking. I detailed my thoughts about the current market and my plan in this thread.
Theme and Template
I received a few emails asking me whether or not theme and template will be updated in V4. The answer is yes. I will also make a new post next month providing info on the improved Theme / Templating system for V4. It will be much easier to maintain than what we currently have with less duplication for templates and better CSS.
As posted on this thread
a while ago, free upgrades are available for customers who purchased after May 16, 2011
post edited by Samuel -