They seem to do it rather often. regardless of how you feel about the reboots/retcons Im curious as to how soon you anticipate another one. Basically I'm asking how long til a renumbering
What do you consider to be "often"? They've only done, what, 2-3 true reboots (of the entire DCU) in their history as a company. I'd hardly call that often.
Unless you are talking about individual books, which would be too much to count for both DC and Marvel.
Anyway, since the title has been changed, they might reboot in 25 years or so, but retcons happen all the time. Matter of fact, quite a few have already happened in the New 52. I.E, Red Robin always being named Red Robin instead of Robin (like the beginning of New 52)
Their average reboot time is five years and six months, but that's counting individual characters or teams being rebooted. The reboot rate for the whole DCU is a little under nine years, so you have DC rebooting completely every 10 years and revamping old characters every five.
I suspect we won't see a whole-universe reboot until DC goes under new management (i.e. when Didio and Lee step down). The New 52 has been steadily declining, as it stands, after having a very successful start. From a business standpoint, whenever new management takes over it would be smart to attempt another reboot in order to get the huge sale boosts. Hopefully, the next reboot will remain steady in sales. This means attempting NOT to alienate long-time fans.
Maybe Action Comics 1000? Currently they are at 934 if you count where they ended the original volume and add all the standard issues for the new volume. That's about 66 issues, which would mean we would see a reboot in...five and a half years...On second thought I like other theories better.