Wal-Mart's pay scheme

This article in Reuters may be of interest, especially to the group that analysed Wal-Mart's pay scheme. It reports that Wal-Mart is increasing the lowest wage paid by the firm to $9 and then to $10. Here are some interesting questions to answer.

1. Why is Wal-Mart increasing wages at this time?
2. What benefits does Wal-Mart anticipate as a result of the increase?
3. How will the increase affect profitability in the short run? In the long run?

Here is the WSJ's article.