Don't hold your breath waiting for a Haswell SP. No time soon if ever.
However, there are competing non-Haswell devices such as the Sony Duo ($1200 - on sale at BestBuy) and Haswell devices such as the Dell XPS 11 ($1200+?) and Samsung ATIV Q ($1500) you may wish to consider as well before pulling the trigger on a SP. Sony Duo out now, ATIV Q very soon and XPS 11 at the holidays.
** Sony Duo is same price as SP 128, has 2 GB more ram, 1920 x 1080 11.6 inch ips screen, full backlit keyboard and 2 usb 3.0 ports and a pen. Unless you are in love with the SP design, this is a better bit of kit for the same money (too bad isn't Haswell, c'mon Sony!). It does weigh about .4 pounds more if that's a big deal. It's devices like this that tell me MS needs to cut their price on the SP or include the keyboard and a year of Office. Right now, for the same money this is clearly a better device.