It is unclear from your post whether or not, as the user is being made aware of the multiple software installations, the user can opt out of any of them. As the installation is proceeding, and the user essentially say "yes" or "no" to any item? Or is everything installed, and the user simply told this fact as it is happening?

The user is not actively saying yes to any item in terms of checking a box or anything. However, the user is made aware of the additional parts of the bundle, and can click the "add or remove software" link below the "Download Google Pack" button to uncheck (or check) any software. I should've linked to Google Pack in the post to clarify, as this is where you end up when you click the ad: http://pack.google.com (note: when I reproduced this by including the AdSense referral ad for a test, I ended up on pack.google.com-plus-some-parameters; however, the installation defaults remained as with above URL).

Don't forget that any current Picasa referral unit will remain supported. As I'm generating a significant part of my earnings with Picasa referrals I hope that Google supports this for a long time.

Despite the fact that Google Pack referral units could generate higher earnings due to the higher payout for Google Pack I assume that the current unit converts better for me – but I'll test this.

The change on the ads happened only in English...