+1 Same here. RAM usage as seen in Activity Monitor will creep up and cross over 3 GB.
Just tried this manually. Sync, Sync, Sync, Sync, memory usage as seen in activity monitor, increases by ~1 MB each time and does not come down.
Another observation. Worked on EN before bed, put mac to sleep, woke up next day and did the same to the mac & voila, RAM usage spiked to 1.5 GB.