Could Litecoin take it down because its faster transfer rate?
Forget slow confirms.
"Bitcoin network is restricted to a sustained rate of 7 tps [...] VISA handles on average around 2,000 transactions per second (tps), so call it a daily peak rate of 4,000 tps."--Bitcoin wiki, https://en.bitcoin.it/wiki/Scalability
World currency
To fix this issue we would need to mine a fork of the bitcoin chain that has a larger block size (i think this has been proposed by someone). I'm guessing the issue with that is the storage requirements to have the chain on a harddrive would skyrocket.