Wonkette had a brief summary on their site...
"At risk of oversimplification, the Byrd rule is designed to ensure that reconciliation is used to only make budgetary fixes, not policy ones, to existing legislation. Presuming the House passes the Senate bill, the House will then pass a reconciliation fix to the bill, after which the Senate will then try to pass that fix, too.
At this point Senate GOPers will repeatedly invoke the Byrd rule to ask the parliamentarian to strip individual provisions (ones fixing this or that in the original bill) out of the fix, on the grounds that they are policy fixes. If individual provisions are stripped, it would change the Senate’s version of the overall fix.
That would force the House to vote on it again and again, stalling the process further.
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There’s a larger game plan here. By making it clear they will do their best to tie reconciliation in procedural knots, Republicans are hoping to frighten House Dems into believing reconciliation is doomed. If House Dems are persuaded that the fix later will fail, they will be less likely to pass the original Senate bill in the first place, perhaps killing it."
on edit: added link
http://wonkette.com/414069/reconciliation-will-be-scarier-than-one-million-halloweens