Sony is definitely planning something, it looks like the release of their new laptop lineup (or at least some major additions), including the 13.3-inch VGN Z-Series (and possibly the SR Series as well.
They have a teaser up on the main Sony Style USA webiste (view it here).
It could be that this is related to a release of other products in Europe in and Asia as well (hence the odd timing, after the close of the normal business day).
The teaser has an image of a green on/off button, with scrolling text that repeats:
Below that is the tagline:
“Coming 8:00 p.m. CT on Monday, July 14.