Hi Steve,
I've been following this through various sources, as I have a trip booked at the end of March and have the same concerns you've raised.
A friend of mine was in Marrakech at the end of January when troubles kicked off in Egypt. She asked the locals if they thought the same would happen in Morocco, and was told that it's really different there as the government system is different / they have a lot of respect for their king.
Not sure where you're from, but as a British citizen, I've signed up to British Embassy alerts by e-mail (it's really good, you can actually enter details of where you're going and when, so they send you any relevant info by e-mail - I've had nothing about Morocco so far) I'm also following them on Facebook, and they provide regular updates, which have mainly been about Libya - advice on how to get out etc.
I think, from what I've read, if there are any protests in Morocco, they'll be managed better, you'll know where and when they're happening, and you just need to avoid the area at that time. For example, I read on the Thorntree forum that there may be a protest on 20th March, and the advice seems to be to just stay away.
Another thing is, a lot of things can be media hyped, and North Africa is a huge region to group as one. For example, I was in Israel this time last year, and my boyfriends boss rang us to see if we were OK, as news reports stated huge riots in Jerusalem - we saw nothing like that, and that was where we were at the time!
It would be useful if anyone who is there now could contribute to this forum, so hopefully someone will see it and confirm all is ok, as I am really excited about going to Morocco, and I don't want to have to cancel :-( And if you could let us know when you've been as well, that'd be top, as I think you're going before me by the sound of it?!
