There are 2 diff ways to configure hotmail into outlook 2010. One using the outlook connector, no pst files for this type. Another using pop3 settings. Using this, u can point ur mails to ur orig outlook pst. This can be done while setting up. If not, open account settings, select the hotmail account and click on change folder and select the folder inside ur personal folder i.e other than hotmail.
Other option is to recreate the hotmail account and specify ur orig outlook pst for email delivery.
Hope I am clear.