in that case you can make your own global message variable, and assign it from within the receiving script.
A problem here: If you broadcast a different message, that one above will still run.
yep, you'll need to check what you receive with the "any message" option.
What if it is a message that changes?
look at my example, you could encode kinds of messages by choosing different prefixes, like "score:".
Ah, makes sence.
actually, I'm not totally happy with this just yet, but it's one way that already works...
Hey jens, Why don't you add a reverse codification feature?
e.g.
print("Hello, world!") ->
[scratchblocks]
say[Hello, world!]
[/scratchblocks]
Why not just write a parser yourself?
Cause it's difficult. Try yourself.
It's not that hard...
OK, Then make one.
@jens I think the message block is useful (Especially for creating my AI)! So please don't take it away!
it's still there, it's just a dev mode block now.
If you have a need for the existing global 
that can't be easily overcome with the new 
upvar then can I suggest just creating a global variable called last message and adding a small script to your stage
thank you, Simon, this is exactly the solution for those if (I receive _) situations I have in mind.
[EDIT - THIS POST INFORMATION IS OUT OF DATE but just leaving it up]
There's been a major visual change - the broadcast blocks have been changed to send blocks
Check it out 
Existing projects with broadcast blocks should be automatically converted to new syntax
E.g V6
gets automatically converted to this in V7
Note - Jens has warned me that this change might get reverted back to original method (as any V7 dev thing can) as there might be a lot of BJC stuff that needs changing
Why did you flag my post? I was just joking.
It looks like the new send blocks were renamed to broadcasts and the second drop-down can now be collapsed.
Also, the message upvar in the when key pressed and when I receive hat blocks are now only expandable when the any option is selected from the drop-down.