QNAP 451+?

I'm currently looking at a 4 bay NAS. My current NAS is a 2TB MyBookLive. I'm looking to expand the features set and am mostly considering a QNAP 453 Pro (or the recently announced 453 mini). The 463 is also tempting, although I'm unsure about the AMD CPU.

However, looking at B&H's site, I see reference to a QNAP 451+ (which seems to be unannounced).

http://www.bhphotovideo.com/c/product/1184489-REG/qnap_ts_451_2g_us_ts_451_4_bay_2gb_personal.html

This is obviously separate...

QNAP 451+?