Will my bitcoin wallet take prohibitively long to sync as daily transaction volumes grow? I'm using Bitcoin-qt on Mac and it's been a few weeks since I last fired it up, so it's doing a sync. I've waited a few hours now, despite being on powerful hardware and a fibre connection to the web.

If I understand it correctly, the sync involves some processing for every Bitcoin transaction performed globally. In the bright future of Bitcoin, when people are buying Mars bars with them, won't the sync be prohibitively slow due to sheer volume?

Or are we hoping Moore's law will offset this growth?
The points mentioned in this answer apply here. The key points are:


End users won't be expected to run full nodes such as bitcoin-qt, but rather lightweight clients such as Multibit or Electrum.
Not all Bitcoin payments need to take the form of Bitcoin transactions; most will probably take some form of trustless, instant, off-the-chain Bitcoin payments