I often read that the Bitcoin system has limits for the amount of transactions processed worldwide in a given time frame. I think it has to do with the block chain and the mining, but I am no expert in this topic.

When such payment systems spread, couldn't they overburden the system?

To make it clear: I am a huge friend of alternative payment systems, particularly if they make it possible to have smaller amounts paid on the web without hassle and with less transaction fees. But there are always the people that warn against Bitcoin because of diverse reasons (keywords: inherent limits, Ponzy scheme).

What do you think/know?