Patrick,
I'm going to expose the soft underbelly of our industry, but on most loans we only do a few hours of paperwork. Problem is that we spend 40 hours looking people who need us to do paperwork! 
VA has a list of settlement fee's that can not be charged to the borrower. The most typical that you'll see on a IRRRL being paid by the broker are:
Processing, Underwriting, Doc Prep, Title Closing & Tax Certificate
These fee's will add up to $800-$1,300 depending on who's used to provide these services. Outside of these fee's you'll still have a mortgage credit rating (similar to a credit report but just the mortgage), title insurance, recording fees, escrows for taxes & insurance and the VA funding fee unless you're exempt. Also depending on your loan package an origination fee that gets capped at no more than 1%.
Also I would add, just because there is less qualifications for the borrower to get an IRRRL doesn't mean the broker is doing less work. They should still be shopping your loan for the best rate, completing application and disclosures, running updated figures when payoffs come in and monitoring the loan underwriting (all the same things we do on a normal refinance). On a typical loan an Originator might do 2-3 hours of file work and on a streamline that might be 2-2 1/2. The reason we like them so much isn't that they are less work but rather there is much less fall-out. We don't have to worry about low appraisals, lost jobs, credit history, etc. In terms of stress and brain damage they are half a normal loan at least.
I would take a guess and say that I don't see VA loans going under 5.0% unless you're willing to pay discount points. Biggest reason is VA loans follow the Ginnie coupons (like fannie but for government) and the Ginnie 1 (most popular and traded) moves in .50% increments. Meaning we'll need to get to 4.50% paying 1% or better to be able to offer it to the public (because we're paying settlement fee's and can't charge more than 1%). Of course there are exceptions for larger loans or if your broker is just feeling generous (code for desperate).
If you can get 5% right now without paying any origination or discount points that's a good loan. If you can't then shop around or wait and see.