Apparently Microsoft has increased Data Cap from 20 MB to higher limit when downloading and installing any app from Windows Phone Store on Cellular (3G) network. Earlier if we try to download and install any app of size above 20 MB on Cellular network, we got message that switch to WiFi network to download bigger apps. But today I was able to download and install app of size 27 MB using 3G Network. Earlier when I had tried to install that app, I got message popup asking me to switch to WiFi
Some good development from Microsoft regarding Windows Phone!