My understanding is that blocks don't quite work right in squeak.
Could someone refresh me about exactly what way they don't work right?
Apparently they are not "full closures", but that doesn't mean much to
me. 

Also, what's the current status of the redo that fixes this (VI4, I
think)?  That is, when is it going to get merged in?

Thanks to Ned's advice, I'm using blocks to fix a problem I had.  I
thought I'd better check that I'm using blocks appropriately for
squeak.

I looked on the swiki, but the stuff I found on blocks there either
points to VI4 (which, again, I understand is not in the mainline 3.2
or 3.4) or dives directly into the internals of block implementation.
I'm looking for something from the standpoint of the language user, not
the designer.  And I want to know how it works now, not how it will
work when it "works".

While I'm on the subject of blocks, I recall that in VisualWorks there
were big block performance differences depending on how much the
external environment was referenced (the details are a bit hazy; I
think it was called open vs closed blocks).  Are there any similar
performance issues with blocks in squeak?

Thanks.