In the US the areas I've toured and driven through using Google Maps tends to be up to date by 1-3 years. Certain areas I'm intimately familiar with I've checked out on Google Earth and seen they update the images every year or so.

I'm along the lines of Mev's post though. I like to use Google Maps to get a general feel for how I should get from A to B, and that's that. I just wing it from there. Making sure I pay attention to major N/S and E/W roads while I check out the maps. When I stop for food or drink I like to take another look just to update my mental image of where I'm going.

In the U.S. we have a lot of good signage that makes it so you really don't need to keep your nose in a map to know where you're going.