Why not aio (asynchronous/anonymous i/o) or simply io? It's all about I/O, not about the particular construct (a lambda), right? A couple of examples rewritten with the new keyword:

my $q = io { print "Hello world!\n" };
$q->wait;

$q = io { 
    context io { 2 }, io { 3 };
    tails { sort @_ };
};
print $q->wait;
[download]

Of course, you would need to rename the current io predicate to something else; perhaps io_trigger?

I also suggest moving the Stream I/O section near the beginning of the documentation file. Yes, the mathematically logical order is to introduce low-level things first, then define high-level things using them, but my interest was only sparked after reading the Stream I/O section. Unfortunately it's at the bottom, and I suspect many people will stop reading or browsing before reaching it.

Alternatively, move the high-level examples to the synopsis before the low-level ones. The low-level examples are mostly toy examples. If you can't think of any better ones right now, remove them. For instance, why would I want to create a "pipeline that waits for 2 lambdas"?