You don't want to get caught in the loop of waiting for new tech, you'll be stuck there forever. However, if you don't immediately need the computer, in this case I think it would be worthwhile.
Around the same time that 1155 is released, ATI is supposed to be shipping their 6000 series, which should do at least one of the two following things: a) provide better performance than the nVidia 4nn and ATI 5nnn series, b) affect the prices of at least the current ATI lineup, and possibly the nVidia lineup. That might change the value of current offerings significantly.
Also, there's supposed to be a change in SSD manufacturing tech, so that may make SSDs more affordable.
You might consider waiting until Black Friday, newegg generally has some pretty sweet sales/deals.