I agree with the OP that it would be nice to have a way of viewing questions that I, personally, have not viewed.
In practice, my way of doing the equivalent is to (a) view all questions as they show up in the "latest" stack. This could also be done by subscribing to the RSS feed as suggested by Qiaochu Yuan. And (b) I look at the older questions using the question list in "newest" order. For example, I came upon this question by looking at page 19 of the meta mathematics question list: http://meta.math.stackexchange.com/questions?page=19&sort=newest
I keep a link in my favorites to the meta mathematics question list. As I read more questions, I update the link (by writing over it) to the last page I've visited. Then I can easily see which questions I've already read by using the color difference provided by my browser.
For me, this has been an adequate solution.