There are pluses and minuses of such decision. I have seen a blogger doing this and this made me wonder of what effect his decision will have on his blog.

Pluses include:
1. Your articles will not seem outdated.
2. Your article is more likely to be linked by others as people in general like to link to something fresh, and your article will always appear as fresh.
3. You might get more comments as your articles will seem to be less outdated.

Here are some potential minuses:
1. Some readers might actually prefer to know when an article was released.
2. Not putting a date on an article does not change the order of articles. Those situated later will still seem to be outdated even though there will be no date on them.
3. The whole idea is innovative and might not be accepted well in the blogosphere.