Yes, you will be charged if you want to continue hosting on Azure.
Check this blog for details.
To quote MS
`If you elect not to upgrade, on February 1, 2010 your CTP accounts will be disabled and any Windows Azure Storage will be made read-only
For the time being, only customers in select markets around the world will be able to upgrade to the full version of Windows Azure. Microsoft is currently accepting customers with the credit card billing address in one of the following countries, with the promise that additional markets will be added in the future: Austria, Belgium, Canada, Denmark, Finland, France, Germany, Ireland, India, Italy, Japan, Netherlands, New Zealand, Norway, Portugal, Singapore, Spain, Sweden, Switzerland, UK, and United States.
“If you upgrade your CTP accounts during the month of January, 2010, all Windows Azure platform usage incurred during this month will be at no charge. You will also have full visibility during this month to your Windows Azure platform usage. Billing and SLAs for all commercial accounts will begin on February 1st, 2010,” the Windows Azure team member said
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