Now it is confirmed, the comet P/2003 K2 (Christensen) and the 2008 X4 are the same comet. And it is periodic with a P =5.72 years.
I have added the epherides on my site; it will reach the magnitude 9.1, but it will be very difficult to observe because of the proximity to the Sun.
www.pierpaoloricci.it/comete/comete_eng.htm