The XSE line is gone. The reasoning being stated publicly is that Colt took a look at their product offerings and eliminated models not in high demand in order to focus on providing a bigger supply of the guns their customers want.
This implies that the best selling Colt pistols are the 1991 line, the Series 70 Repros, The Gold Cup, and the Rail Gun (which has recently been updated). The Combat Elite is the only non-rail XSE-based gun remaining in the lineup.
The adds on gunbroker should be entertaining for the next couple months.