Outside of a few smartphones, 4K video capture has largely been limited to pro-level hardware; the SD cards in regular cameras frequently can't handle so many pixels at once. That won't be a problem in the near future, as the SD Association has just unveiled an Ultra High Speed Class 3 (U3) card format that's up to the job. The spec guarantees write performance of at least 30 MB/s, or enough bandwidth to record 4K clips without hiccups. You'll have to wait for U3-capable devices and cards to begin shooting, but it shouldn't be long before you can produce footage worthy of your Ultra HD TV.