Delta has introduced revenue-based awards today and higher priced upgrades for travel beyond June 1, 2016. You can currently book award travel and upgrades through June 9, 2016.

Delta's Statement
Here's what Delta says about the changes:
We know your miles are important, so we want to provide the most notice possible regarding Award price changes. For travel on or after June 1, 2016, the number of miles needed will change based on destination, demand and other considerations. But most Award prices will remain unchanged.

Update 7/9/15: All these deals are dead. The Citi® Hilton HHonors™ Visa Signature® Card has come out with an even better offer! 75,000 bonus points after spending $2k in the first three months.

Today (June 30) the 60k and 50k Delta credit card offers expire, the 50k Hilton credit card offer expires, and the ability to buy IHG points for 0.575 cents ends. It's a big day for procrastinators.

I do not know the exact times the credit card offers end.

Update 7/9/15: All these deals are dead. The Citi® Hilton HHonors™ Visa Signature® Card has come out with an even better offer! 75,000 bonus points after spending $2k in the first three months.

Today (June 30) the 60k and 50k Delta credit card offers expire, the 50k Hilton credit card offer expires, and the ability to buy IHG points for 0.575 cents ends. It's a big day for procrastinators.

I do not know the exact times the credit card offers end.

Alitalia Business Class award space is wide open in Spring 2016 from New York and Boston to Rome for 62,500 Delta miles each way. Many days have three award seats in nearly flat beds.

According to Delta's SkyMiles FAQs, mixed cabin awards are no longer allowed.

Mixed cabin awards used to be explicitly allowed (and indeed this FAQ at a slightly different URL has the old language.)

If mixed cabin awards were totally banned, that would terrible news. I can see three possible maladies:

Delta has "five" cabins: economy, Business, Business Elite, First, and One. Each plane has only two cabins but the front cabin is branded several ways.

Yesterday I reported that some Delta domestic awards cost only 5,000 SkyMiles one way, a 60% discount on the prevailing 12,500 mile rate we expect from legacy carriers. Other routes cost 10,000 SkyMiles one way.

Delta SkyMiles have access to the best award space to all of Argentina--not just Buenos Aires--year round in economy and Business Class.

The backbone of the award space is AeroMexico availability on its daily flights from Mexico City to Buenos Aires.

This is the ninth post in a monthlong series that started here. Each post will take about two minutes to read and may include an action item that takes the reader another two minutes to complete. I am writing this for an audience of people who know nothing about frequent flyer miles, and my goal is that by the end, you know enough to fly for free anywhere you want to go.
Where We Are and Where We’re Going
We’re in the section on redeeming miles.

This blog became famous because I was the first to articulate how to book free one ways on United and US Airways awards.

A free one way is a one way trip to or from your home airport that is tacked onto another award for no extra miles.

I was explaining to my brother the changes that Delta has made in 2015, and I mentioned that the one I just couldn't believe was that Delta eliminated its award chart. It seems self-evident to all of us in the miles game that Delta eliminating its award chart is insane and unjustifiable.

(Delta deleted the chart from its site, but the possible priced for awards are the same now as they were when the chart was on delta.com.