2 GB of memory sure does make a difference. In practice though, I wonder how much this will really impact the typical user. Do people usually keep tabs open in Safari with the intent of going back to them?
Also, this is without the user exiting Safari. If you open these tabs in the morning and then go back to them at the end of the day, the apps that you've used throughout the day would surely have taken that memory back from these tabs, right?