When will the next version of avast antivirus be released 
If you are looking for avast! 5, this press release may give you a hint:
http://www.avast.com/eng/press-release-avast-celebrates-50-000-000th-registered-user.html
If you meant Avast! 5, the latest information was posted by, Vlk, one of Alwil employees in another thread.
It depends on what version you are talking about, the program is continually updated and there are periodic updates.
If you are talking about version 5.0 - As has been asked before, when it is ready, there has been lots of speculation but no firm date, but you will hear about it here first.
Oh, I missed the thread.
Thank you very much, Rumpelstiltskin.
No problem, Iso-G. I happened to come across the thread only yesterday and, otherwise, I could have missed it, too. ;D
Also, as DavidR pointed out, the date is not fixed even the post is “semi-official.”