But if they change that to Google Patent, you will say that is a "tip", so Google will be blamed again...

To clarify, I do not blame Google for tips in general – I do blame them for some of the tips which I don't consider neutral (which I don't even consider real "tips"). But, for example, I consider the image search tip more or less fair game, because it's leading to another semi-neutral search/ search result. A potential patents tip would need to be evaluated on its own basis... I guess one option would be to make it look like Google's existing maps onebox, allowing the user to choose from a set of services (including competitor's ones). Even linking straight to a result from Google might be an option you'd have to analyze anew, because it's a search result (and not even with content in a commercial niche – USPTO is a non-commercial, public-domain material government website).

It's also worth noting that if you enter a query such as GOOG or MSFT then Google will offer you quite a few websites to view the specific company information.

I think they should use Google Patent

Oversight, I recon. From my own (phone) experience with Google employees, the left hand often does not know what the right hand does. Coordination within Google did not strike me as particulary good. Perhaps no one thought about this onebox, or no one feels it is important, or no one has time, or no one feels responsible.

This is just like the onebox for searches for placenames on Google.nl, they still point to ViaMichelin and Map24:

http://code.google.com/p/googlebugs/issues/detail?id=3

I added this bug as:

http://code.google.com/p/googlebugs/issues/detail?id=49