Well, in the best case scenario, yes, that would be the number of actuations. However, that would only be true if you’ve never reset the file number naming sequence. Also, once you hit 9999, then it will roll over and start at 0001 again. If you know that you have taken over 10,000 pictures, then you have to add 10,000 to the number to get the total number of shots.
To get an “official” number you can go to http://eoscount.com/ and pay $1.79 to find out for sure. (Note that you’ll have to use Microsoft’s Internet Explorer for it to work correctly)