Here is how you can get the direct links:
The delta can be used to update 10.10.1 or previous beta of 10.10.2 up to current beta build of 10.10.2.
The combo updates 10.10, 10.10.1 or previous beta of 10.10.2 up to current beta of 10.10.2.
Don't post the links on macrumors though because that would breach macrumors rules.
For the delta
Just go to your Library/Updates folder after you start the download from the mas. A new folder with numbers appears. Open it. At first, there will be two files inside which you can open with textedit. The one with extension extraInfo has a link with smd extension. Copy this link. Change the extension in your copy (but NOT in the original file) to pkg and that gives you the direct link.
Once you have your link, if you want to install it without the firmware update, cancel the mac app store download and delete the folder with numbers. Use your direct link to download and install the delta without firmware update.
For the combo
This is a bit harder to find and make appear in the mas.
Make a partition or virtual machine for the first public build 14A389. Be sure never to allow this to be updated. Boot up in 14A389 or run the virtual machine for it.
Install the public beta access utility (available from
https://appleseed.apple.com/sp/betaprogram/ ). Check for software updates. A different thing will show here called the "Combined seed". Click Update. (Don't worry - we will cancel this later).
Go to your Library/Updates folder after you start the download from the mas. A new folder with numbers appears. Open it. At first, there will be two files inside which you can open with textedit. The one with extension extraInfo has a link with smd extension. Copy this link. Change the extension in your copy to pkg and that gives you the direct link for the combo.
Do not let the updating procedure to complete. Click Cancel in the mac app store. If that fails, force quit the mac app store.
Delete the folder with numbers from the Library/Updates folder.
