If you mean Vista or Windows 7 64 Bit, then for LR 3.6 definitely yes: http://www.adobe.com/support/downloads/detail.jsp?ftpID=5308 (I also know from my own experience). Furthermore, LR 3.6 has dedicated 32- and 64-Bit versions (the installer automatically chooses the correct one).
I assume that the same is true for Photoshop Elements 10. In the system requirements it only says "Windows 7": http://www.adobe.com/products/photoshop-elements/tech-specs.html but it should be compatible to 64 Bit, too. However, I don't know whether there is a dedicated 64-Bit version.
