First off, check out the Art Adams cover. That is an awesome picture and it brings back many fond memories of my Avengers-reading career.
Now to the actual stories inside: I was disappointed. I've read the Avengers' Origin story many times so that was nothing new to me. It's interesting as a bit of history but as an origin story it's kinda lame. Even taking into account the state of comics writing at the time which had a different tone and aesthetic from what we're used to today, the actual reason for the formation of the team barely makes sense. The Defenders' origin was far more interesting and it's hard to beat the formation of the Fantastic Four.
The most interesting part is seeing the Hulk during his pre-GRAAH days. It's a reminder that a lot of Hulk's mythology came well after the creation of the character. Also, he's dressed as a clown for a few pages. Don't ask.
Jack Kirby's art would normally be worth the price of admission to me but his style hadn't yet been refined to what we think of as "Kirby!".
The two backup stories were the real disappointments. Dwayne McDuffie attempts a toungue-in-cheek tale of how the Avengers decided who their first chairman would be. It's not entertaining and Michael Avon Oeming's art doesn't help. The Hulk picks up the conference table at one point but I had to be told what he was doing two panels later. Oeming's paintings are nice but if the reader can't figure out what's going on maybe it's time to dial back the style and put a little more substance in there.
The next story has no visual problems at all. Kevin Maguire's art is the best thing about this issue. The writing by Stan Lee is OK but nothing to shell out four bucks for. Stan, looking like a Bwah-ha-ha-era Maxwell Lord, tells us the real origin story of the Avengers. It's cute and it's better than McDuffie's story but it still isn't particularly funny.
Summary: If you're already familiar with the Avengers' origin, save your money. Andy Schmidt and Mark Beazley's decision to go with humorous stories for this first issue was a poor one. There's a bit at the end where they talk about more character-driven backups in future issues. There's a great opportunity for some excellent comic-book tales here and I will keep my eyes open for future issues. The nature of the beast makes this title hit-or-miss, though, so I won't put it in my hold box. I'm glad for the reprints and I like the added value of the backup stories but I'm going to judge this one on a case-by-case basis.