1) When you type a query for, say "san francisco" http://www.google.com/search?sourceid=chrome&ie=UTF-8&q=san+francisco
2) and then click either "Maps" or "News" through the top black buttons.
3) You'll be taken to either "Maps" (http://maps.google.com/maps?hl=en&tab=wl) or "News" (http://news.google.com/nwshp?hl=en&tab=wn) but without your query carried over.
Bottom line: It's frustrating to have to re-type San Francisco.
Potential explanation: Google only wants queries sticky for the new side navigation buttons to other Google properties. Here queries do stick, but one issue is that not all properties contain this new side UI (e.g. Maps) so from one that doesn't, you have no default way to go to another Google property with a sticky query.
Even if Google's feeling is that only the side nav. buttons should be sticky (and perhaps Maps is slow to implement the new UI here) this seems needlessly frustrating. The black buttons on top should be just as sticky, if they're going to be there at all, because Google has established a tradition of sticky queries, and people like them!