Interesting that people banded together to petition for the advertisement/re-model to stay at the train station. It is a sad that it got taken down. This could be inline with some blog posts I did some time ago (here and here), with various advertisers in the Boston area carpeting every single add in a station. Hopefully sponsored remodeling could be the next step in advertisement (and some of these atrocious posters can be taken down). This goes specifically to one of the articles cited in the previously linked posts of the Apple possibly subsidizing Chicago CTAs remodel.
How this might happen with a company like Homebase (think UK Home Depot for those in the states), makes a lot of sense, as that is their market offering, home (and now subway) improvement. How this fits into the market offering of Apple, is not as clear, but I'm sure many people would be excited (as I'm sure some would deplore it as well) to be in an Apple inspired metro station. Seeing how they might physically structure the space to reflect what they offer is intriguing. At the very least, I imagine there being free wireless.
Finally, I can imagine one minor detail that gets in the way of remodels like the one pictured above, and would worry companies like Homebase or Apple in having a permanent advertisement/remodel: MAINTENANCE. I'm lucky enough to live in Cambridge right now, and the metro's are kept extremely clean, very rarely is there a big mess. The place is still very dirty though, just by way of what it is. There are drink spills from time to time. Dirt and soot layers up high places, along walls and pipes. When it rains or snows, the ground becomes very wet and mucky. The Homebase remodel above, however appealing, would not last very long in such an environment. I'm not saying this is a deal breaker, only a challenge to overcome.