It won't be very well performing for mainstream. The 533MHz FSB is very constricting making very lucky that they decided to keep the 1MB cache per core. At $150 its aimed at the low-end of the market, trying to get them to spend a little more and get a dual core. A 820D or 920D is much better for mainstream.
I'm hoping it retains EIST, allowing it to downclock to 1.87 GHz which combined with the lower 533MHz FSB and lower clock speed could actually mean a cool Smithfield dual core.