Was sent this email today from MSN.
Just a short note this time: on Wednesday, March 22, we’ll be raising adCenter traffic levels to 70%. AdCenter customers should start to see an impact to their campaigns beginning Thursday, March 23, however it may take several days to reach 70%. Just like last time, your budget may be impacted due to the increase. Also, as more traffic is directed to adCenter, you should expect a decrease in traffic from your Yahoo! Search campaigns.