On the Web: The 4 Catastrophic Mistakes of Any 
E-Commerce Website Upgrade

Don't fall into this trap. Patience is a virtue, but not when it's costing you revenue every single day.

Remember, your current site is underperforming. Once the overall architecture is right, launch your redesigned site and take advantage of the low-hanging fruit. Then, in the coming months, you can plan for phase two, three, four, etc. Think of these phases as adding features and functionality, not redesigns.