Q: When can we purchase the new storage plans anounced earlier

"Storage plans"?

The only "storage plan" that Apple offers that I know about is an iCloud storage plan.  There has been no price change announced.

iCloud: Check your iCloud storage usage

I do not remember if they indicated when they would be available in the keynote. You can contact Apple if you have a question. This is a user to user support forum, not Apple.

sberman, they did make some adjustments to the fee schedule for iCloud upgrades, indicated in the keynote.

Thanks, Chris ... I saw the entire keynote but missed this.  Don't go to trouble, but do you happen to recall which general area this was mentioned (e.g., iPhone, iPad, Apple TV)?

To be honest not exactly. I've got the podcast downloaded, maybe I can skim it real quick and see.

As I say, please don't go to trouble.  I did find this list of current prices for the OP:

iCloud storage pricing - Apple Support

This article makes it look like the price reductions have already occurred:

http://www.macrumors.com/2015/09/09/apple-announces-cheaper-icloud-plans/

Yes, I believe those are the new prices. I believe it started at 20GB. I believe it was while Phil was on stage, but I can't find it right now. I'm ready for bed, teach in the morning. I'm going to watch again between classes tomorrow, so I'll post a timestamp for you when I see it.

EDIT: According to that MacRumors article, the low end is now 50GB instead of 20, at the same price that 20 was, $0.99/month in the US. Other countries depending on the exchange rate.

Thanks for all your trouble.  Good night.

No trouble at all. That is what friends are for!