After upgrading to OS X 10.9 Mavericks, no scanner device appears in DTPO > File > Import > From Scanner or Camera. The scanner (Canon MP530 multi-function device) does not appear in Image Capture, but does and continues to work as expected in Adobe Acrobat and in Canon’s MP Navigator app. Also, the MP530 continues to print as expected.
OS X 10.9 has a new scanner API (IIRC Apple dumped TWAIN), so many scanners need driver updates. If a scanner company did not provide an updated driver to Apple for Mavericks, the scanner won’t work anymore. Unfortunately, this affects many older Canon scanners, so yours might well be among those. You should check the Canon website for compatibility info.
This only affects scanner support on the operating system level (which DEVONthink probably uses), so of course applications which address the scanner directly (such as Adobe Acrobat or Canon’s MP Navigator app) will continue to work.