Once you have set up a Firefox Sync account and set your preferences, you may remove the X-marks addon and begin using Firefox Sync immediately.

A pity there is no web page to get your synched bookmarks when using public PCs or accessing them via a smartphone... This is a feature I will miss from Xmarks!

SerguiA, If you google it, you'll find there are a lots of on-line bookmark storage services. This one is what I have been using:

http://www.bookmarktracker.com/bt/home

I agree with that, it's a pity. I'll miss Xmarks too

with Xmarks (RIP) i could bookmark sync with other browsers (IE, chrome) too. that was a great help. i suppose can't do the same with ff sync