There is double the amount of mainland tier, from 1024 square meters to 2048. The land can also be split between mainland owned and a Linden home (they're available either in 512 or 1024 square meter parcels).
Later on, 2048 square meter parcel Linden Homes will be an option for Premium Plus accounts. It was hinted this might be done towards the end of the year.
Able to claim or request a specific Linden Home, as long as it's still "available through the duration of the time in which you place the request through support manually." Patch stated he had to "heavily caveat" this detail, "the whole system is automated, and not even we can beat it ourselves." In theory, two or three Premium Plus residents could become close neighbors.
"You can get two land experiences that you can make," Premium only having the option to create one.
The sign-up bonus is 3000 Linden dollars (for Premium, it is 1000 L).
The weekly stipend is more than doubled, from 300 to 650 Linden dollars.
The number of groups one can be in doubles from 72 to 140 (basic is 42).
The cap for stored messages when offline goes up from 80 to 160.
No fees to upload textures and sounds. Mesh and animesh upload fees will change in the future.
The group creation fee is reduced from 100 Linden dollars to ten Lindens.
The cost to list events on the Linden blog is eliminated.
The number of Animesh attachments will increase (Patch stated from one to two, but this is the increase from basic to Premium).
Premium Plus members get a "special support phone line" for direct concierge level support, with a toll-free 1-800 number, with Residents from outside the United States also able to use.
The Lab will make available sandboxes reserved only for Premium Plus accounts in the future.
The cost for all this is $29.99 US dollars a month, with a $24.99 introductory price, or $249.00 USD if charged yearly, slightly more than double the $11.99 USD monthly and $99 yearly fees for Premium.
There are no changes to Basic or Premium accounts.
As of the writing of this article, there is no post on the Linden blog, or page on their website to sign up for Premium Plus. Patch stated there should be in a day or two.
Addition: We originally gave $24.99 a month as the price, without saying that was the introduction offer. Sorry about the error.