If you where expecting a Windows 8 app update (maybe the recent update to the in built People App, Mail, Calendar &Music App) but are not being offered it, then you can try forcing  the app to be updated.  Here is how:

Firstly open the Windows Store and go to settings in the charm bar

settings charm

then select App Updates

app updates in Windows 8 Store

Check for updates

app updates check

Select which apps you want to update

app updates apps

press install and your apps should get updated

installing apps

Get more help for Apps and the Windows Store

Rob