In the current CVS version,
xticlabels generates the labels, but no ticks. With 4.6.3 it works. Consider the following example:
set offset 0.5,0.5,0,0 plot '-' using 2:2:xtic(1) with lines Jan 1 Feb 2 Mar 3 Apr 4 e
The attached image shows on the left the output with 4.6.3 with labels and ticks, and on the right the CVS output without ticks.