Bitcoin transactions are happening almost instantly, but the 10 minutes that you were referring to is for the confirmation time... Depending on their fees and the network load, it might take you longer before you get the first confirmation.

Regarding its speed, it can happen temporarily when there's a huge inflow of miners or rather hash rates, but because of the difficulty adjustments ^{[every 2016 blocks (roughly 2 weeks)]}, it wouldn't last very long.