Microsoft has released a preview version of Internet Explorer 10 for Windows 7 in both 32-bit and 64-bit flavors. Changes are mostly under the hood. There are very few visual differences from IE9 but the upgrade delivers some major performance improvements. An upgraded Javascript engine, assorted rendering improvements and other tweaks give IE0 Release Preview a major performance boost over IE9.
Do Not Track is now enabled by default, supposedly to enhance your privacy. But as some companies have said they'll ignore this as it's not based on a user decision to opt out.
Enhanced Protected Mode further isolates the browser to limit what malware can do, and can be enabled at Tools > Internet Options > Advanced > Security. But this will disable any extensions which aren't compatible with the new technology.
Internet Explorer 10 for Windows 7