This is still a feature.
You can still select File>Import.... in Photoshop to get to your scanner. In Windows 32 twain, Windows 64 and 32 WIA, and on Mac via toolkit. Twain is not supported in windows 64 bit. The gotcha here is that many of the companies who make the scanners do not yet have drivers for 64 bit.
PFerguson said it even better, here is his explanation:
On the Mac, Photoshop CS6 is a 64-bit only application, and so in order for TWAIN to work in Photoshop, you must install a 64-bit TWAIN driver for your scanner. Unfortunately, very few scanner manufacturers have released 64-bit TWAIN drivers for their scanners, so the number of scanners which will work in Photoshop CS6 is limited by that situation. In practice, this means most people will not be able to use TWAIN for scanning in Photoshop CS6 on the Mac, but we have added support for scanning using native Cocoa scanning APIs (ImageKit) added by Apple in Snow Leopard. This can be found under the File > Import > Images from Device... menu command. (Note that ImageKit scanning is fairly basic, and does not provide the flexibility or control of more full featured, commercially available scanning applications.)
The situation on Windows is somewhat different, but has its own limitations. First, TWAIN is not supported at all in the 64-bit version of Photoshop CS6; this has been true for every 64-bit version of Photoshop. Microsoft does not provide a 64-bit TWAIN DLL in Windows, and as on the Mac, there are virtually no 64-bit TWAIN drivers ever if Microsoft did support 64-bit TWAIN. So 64-bit is (and has always been) a non-supported environment on Windows. Microsoft provides scanning support through WIA, and Photoshop does include a WIA plugin to support direct scanning into Photoshop through that mechanism.
You can perform TWAIN scanning in the Windows 32-bit version of Photoshop CS6, and it should work exactly as it does in earlier versions of Photoshop. As with CS5, you do need to download and install the TWAIN plugin for Photoshop from the Adobe web site; the TWAIN plugin is not part of the normal Photoshop installation process.