If I receive a Skype call from Europe - do I get charged roaming fees by AIS in Thailand?

Anyone know?

If you have registered your AIS mobile number with Skype-IN service then incoming Skype calls to your AIS number will charged as a LOCAL call from an out-of-network source.

So it really depends on your calling plan. If you are normally charged minutes usage on in-Thailand incoming landline calls then you will be charged for the incoming Skype forwarded call.