nope Thankfully, as reported on inc gamers, the issues have since been resolved and all friend-invite codes for the beta should now work as intended. Current StarCraft 2 beta participants who received a code can now invite a friend to join them in the beta.
The StarCraft 2 beta is currently being enjoyed by many of our community members, and our first impressions over here at Shacknews have been quite positive.
Blizzard's still aiming to release StarCraft 2: Wings of Liberty for the PC and Mac sometime during the first half of this year. Fingers crossed.