You can have up to 200 AdSense for Content Host channels and 200 AdSense for Search Host channels. These are in addition to the 200 channels you have for AdSense for Content, and 200 for AdSense for Search. There are currently no plans to offer more than 200 channels per product.
I'm not quite sure if the 200 channel restriction is for all channels or just active channels. Have you tried to deactivate your 200 channels and then adding a further 200, then switching between them. I know it isn't a great solution but if it works then you could have as many channels as you like.
I can create 500 channel.... I had close to 200 channel .. then google upgraded me to 500 channel... Ani
I have more than 200 channels right now..... and i can create a total of 500 channels... Many people who were using close to 200 channels have got their numbers increased by google. Ani
Your info is in error I have mine maxed out (500) and if I could get thousands, I'd use them, at least as long as there is going to be inherent errors in the adsense/analytics integration.