[muyuu]

5 minutes is still a perfectly acceptable block time. It only gets problematic as network latency can be significant in block discovery chances. This happens under a few seconds per block.

There are alt-coins working with 1 minute blocks and they behave just fine. Provided hash power is spread among the network, there is absolutely no problem with this, and it won't be long until we go back to 10 minute-ish blocks.