New Computer: How to transfer Apps???

If you lose all your apps, when you go to get them again from the iTunes store, it will say "You have already purchased this app, click OK to download again". You are able to then re-download all your apps again, including the ones that cost, at no charge.

Note: You must get the apps under the same account as you have previously used.
Second Note: When getting apps that you pay for, the popup that says: "Are you sure you want to purchase this app..." comes up still, so just click OK and then the "You have already purchased this app" message will appear.

Source:
Personal experience

 

Moving your iTunes library to the new MBP will also move your iPhone apps.

 

I also sync my 16g with 2 computer, all the apps that I have on the 16g will backup to either computer if I sync it, and I also have the same warning message like yours, that saying it will replace all data from my computer to iphone, but I proceed and apps in iphone will get backup to the computer.

 

the way I did it was

1) open up the location of the apps.
2) copy them to a flash drive
3) put the flash drive on the new pc/mac
4) drag all the alls on to the apps window in iTunes.

works a treat
hope that helps

 

transfer apps

to transfer apps and all data, plug in your device, click file-transfer purchases from ___...