Ability to select multiple actions !! The biggest and most important change. Now you can rearrange many actions at once. Use Control and Shift to select the actions you want. This ruins the complaint that its "slow" to move actions up and down 1 by one. Now its faster than programming for me.
Ability to move a block of actions to the very top and very bottom of the actions list
The Speed of moving actions up and down is really fast now because every time an action is moved it doesn't save it. You can go into Preferences and select 'Auto save action changes on Room change' or whatever, or click the Save icon to save the changes in that room when you're done. It's by the Up Down Delete buttons.
Piracy detection! Yes, 2.7 goes on the hunt for DSGM torrents, DIZ files and the like. It doesn't stop you using the program, but it gives you a nice little note if it detects anything, giving you the option to buy the program, or *swear* it's a mistake.
You can now remove backgrounds by Right-clicking the screen (I missed this out when I rewrote the screen click handler). Also you can right click to remove backgrounds without having to select a background in the resources treeview. This makes things alot easier, you can now have a sprite selected but still remove backgrounds
Deleting a rooom no longer removes the first room on the list effectively ruining your game. This is a bug that was caught by the beta testers. Keep looking for bugs! smile.gif
Really fast Registration & Boot as I rewrote my PHP Registration library so DS Game Maker only has to make 1 call to the server.
Cleared up the last of the file dependencies, now DSGM should never lock Sprites or Backgrounds so you can't edit them outside the IDE.
Removed all but the Blank Project template. Awating more from anyone with spare time. Also removed the sample graphics which were for the other templates and were non-generic
A new settings/preferences system means you can edit settings outside the program. It makes the preferences system faster to load and save, and if you upgrade to a newer version of the program, you can just take the Settings file with you, instead of having to customize everything again.

Minor changes (but still important):

Changes to the Preferences window should make the program faster. Also added some icons to the Default Resource Type drop down boxes. The layout is also much cleaner and easier to work with.
The loop action now uses a s32 variable instead of a u8, allowing you to loop to numbers greater than 256. You are also able to scroll backgrounds using a loop to a position further than 256 as a result of this change.
Also if you are using the Unregistered version you can no longer edit the first 2 game description text fields. All 3 description lines will advertise DS Game Maker until you Register the program
Faster compile with James' new sprite indexer, which may also clear up some reported bugs with the pallets starting at 1, not 0 (although I could never replicate it)
Game Description Text information fields now have a maximum input length of 23 characters. This is the length of text the R4 can display
The Game Description text tab in Game Settings now