I agree googleman. As of now around 30 congress and 3 senators or so are boycotting. Out of 535 that is very little. If this speech goes well and he wins the election, both of which are probable, he will be ahead of any other leader in Israels History in stature (including Begin, Sharon, Ben Gourion , etc). The last 24 hours the Obama admin has eased up the pressure on him as they must sense that they lost this battle.
Nobody is going to care in a week or even a day if the invitation lacked protocol or Not and nobody can do a better job on this subject in a prepared speech then BIBI. Also according to a new Gallup poll today, Bibi has a much more fav / unfav rating then Obama does in the USA.