Here is a freeware tool called Aero Enabler, which will lets you enable Aero in Windows 7 (also Vista) Home Basic editions.
Moreover, the tool has an option to disable Hardware Check. By disabling Hardware Check, you can enable Aero without meeting the WDDM specifications.
Since Microsoft clearly states that features for all editions of Windows 7 are stored on the machine, there is no surprise about this tool.
Download Aero Enabler for Windows 7 Home Basic (also Vista Home Basic).