Comments by Dev_2580 (Top 1 by date)

Thanks for the reply. You're absolutely right in saying that its the property only changes when you lose focus. In Silverlight 5 you can set UpdateSourceTrigger=PropertyChanged in your binding and the ViewModel property is set when text property changes and not on lose focus.

Got my answer here.
http://social.msdn.microsoft.com/Forums/en-US/8051216a-a813-4d7f-9d02-cc0f0c5ec562/ui-sets-viewmodel-property-after-command-fired

Cheers!