I can't speak on the property values in Mount Pleasant, hopefully another agent from that area may be here on Trulia and can provide you with that information.
As far as Waukesha and Oak Creek. Both of these cities had appreciation in value of approximately 4-6% /yr. up until around 2006. Since then, for the most part - values have been modest or flat. As you know most properties have had some re-adjustment in value in the last 1 1/2-2 yrs. There was an abundance of inventory, which has made it a Buyer's market. Slowly we are seeing some of the excess inventory starting to be sold. There are some great values for Buyers who see the investment potential.
Since all the factors that made these areas desireable in the past still exist, I would imagine when the market picks up again, that the property values will appreciate accordingly.
Good Luck to you!