For the reasons described in GRADLE-410 , I prefer something like doBefore and doAfter over doFirst and doLast,
and I believe these task-creating declarators shouldn't create anonymous tasks (anon tasks are hard to 'skip').

The anon / hard-to-skip task issue got me think about whether gradle would be better just augmenting createTask,
Perhaps syntax like this might work:

createTask("hello")  {  println "hello world" }

createTask("moo",  doBefore: 'hello' )   { println  "runs before hello task" }
createTask("cow",  doAfter:  'hello')        { println  "runs after hello task" }

As I see it, the 'doAfter' feature is more useful than 'doBefore'
because you can already doBefore via dependsOn. That said,
I'm not lobbying for the removal of doBefore/doFirst because
it's a good symmetric counterpart to doAfter (it may even be
handy for keeping debug operations that wrap the target
lexically out-of-band).

Anyway, I'm hoping that by adding a few more bells & whistles
to createTask(), the overall syntax can be streamlined a bit.