Export Notes from Entourage to Apple Mail
You can Export your notes in Entourage by going to File > Export... or selecting Shift + Command + S, and then check boxing only Notes. When this is exported to a location of your choice (e.g. Desktop), it saves as a .rge. This file type cannot be opened in Apple Mail. Show Package Contents reveals a Notes folder with your exported notes encrypted inside that can only be opened via Entourage. I more or less ran into a dead end trying to figure this out for you.  As far as I could figure out, this cannot be done any easier way than the following:


Open Entourage
Go to Notes
Go to Edit > Select All (or Command + A) to select all of your notes
Go to File > Print (or Command + P) to act like you will print all of your notes
Select PDF > Save As PDF... and select a location of your choice (e.g. Desktop)
Try and import these into Apple Mail, and if unsuccessful import the PDFs you just created into Evernote
Rejoice or sulk depending on the situation and/or your mood


Let me know if you have any futher questions, and I promise that you'll enjoy Evernote if forced to use it. It's the business!