A question in the forums for adCenter API today asked whether the update deadline for customers to move their code from using version 4 to using version 5.1 was changing. The deadline is not changing.
The deadline is the same as previously announced: August 14th.
Our team has provided e-mail and telephone communications in addition to the regular webcasts. We are aware that many customers plan to make the update as the deadline approached. If that has been your plan, now would be the time to finish. Please let us know via the forums or the blog if you have other questions regarding the update.