Yes, the larger surface area of the sensor/focusing screen/mirror are more prone to attracting dust than an APS-C body.
Dust on the sensor/mirror is pretty easy to clean and really isn't a big issue. It is a little more difficult to clean the focusing screen and AF indicator screen, and it is worth noting that dust on the focusing screen/AF indicator screen won't affect IQ, it is simply an annoyance. Also, when using a rocket blower or something similar it is wise to avoid directing air towards the viewfinder area. If you're going to use a rocket blower on the mirror, try to use light puffs, so you don't direct too much air up towards the viewfinder area.
See this link for how to clean the AF screen and AF indicator plate:
http://www.ascent-design.com/photo/Clean5D/