Yes, this data is open and available to all. You can view the number of page views for any given article by visiting http://stats.grok.se/ and entering the exact article name (include underscores in place of spaces), just like the two screenshots below:

Wikipedia article page for "City of Halifax"

http://stats.grok.se

For an example I’m using the City of Halifax in May, 2009:

But other than just being interesting, what else could you possibly do with this? You could gage interest in a particular topic. Plus, since Wikipedia articles often appear high in search results these numbers can give you some insight whether people are searching for this topic (since Google Trends doesn’t give you numbers). Perhaps the most useful is trend analysis. If you wanted to know interest in the topic over the past year, you can easily copy the numbers into an Excel spreadsheet and create a graph for any time period you wanted. Along with Google Trends, you can notice any seasonal or other patterns in interest over time, which can be useful to explain spikes in your website traffic and see whether something is gaining interest, or losing it.

So there you have it, neat eh? If you have any questions just leave them in the comments below.

Referenced from Wikipedia at http://en.wikipedia.org/wiki/Most_viewed_article.