NEW INFO AT BOTTOM OF POST --
I wrote to Hasbro using their Consumer Affairs link under complaints. I asked for information regarding the lack of the newer waves and the blind bags in the US. I fielded the question as both a collector and gift-giver; I have friends with kids that would enjoy some of the new sets.

This was Hasbro's response:

"Thank you for contacting us. We appreciate your taking the time to share your feedback and concerns with us regarding the My Little Pony Friendship is Magic product line.

I understand and appreciate your frustrations ----. In an effort to help you locate specific My Little Pony products, can you advise which products you are looking for? If you can give me an idea, I would be most pleased to follow up with our brand team to see if release dates are available. Also, My Little Pony Blind Bags will be released very soon to the U.S. market.

I look forward to your response.

Thanks!"

What questions should I ask in response?

EDIT: I asked for the release dates -
"Thank you for waiting for my response.

Both products, the Rainbow Dash Camping Trip and Cheerilee Schoolhouse are scheduled to be released around 8/1/11 to U.S. stores. The single packs that include Lily Blossom, Cheerilee, Blossomforth and Dewdrop Dazzle are all currently shipping to stores."

Yay!

blind bags soon in the US??? BEST NEWS EVER!!!!!!!!!!!!!

Woah good job there! I wonder if blind bags might come to the uk too...

yay good news!

even if blind bags are not available here, getting it from the US is a good news! (as long as there are A LOT of them, not just a few bags)

Blind bags in the US?!

*ahem*

SQUEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEE~!!!!

Oh, that is good news! I like the Blind Bag ponies more than the standard G4s anyway. Hey, something to look forward too

That's good news!

That's a positive response! And that's good to know the blind bags will be available in the US at some point.

Wow, I did not see that coming. How awesome!

Oh, that's absolutely awesome! I'll be hitting stores up for sure for some of the Blindbags! My gf in the UK has been wanting some too, so, now it's kind of a waiting game on who gets them first!

Are you going to write back to see if you can get some release dates on some of the other G4 pony lines? :o

Whoa, we're actually getting blind bags?! AWESOME. Even though I JUST got most of them in the mail today, I'm still really excited to hear that. XD I guess there's a chance they won't even be the same ones...?

Thanks for sharing! I'm glad you actually got a useful response out of Hasbro. =P

Thank freaking God those things are coming to the US! I wonder which stores will sell them

Awsome news! Thanks for sharing!

Seriously! OMG that's fantastic!!! yay!

I hope blind bags in the US means they'll be in Canada as well!