Raising tier at such a percentage at a time when many people are taking a long, hard look at their real life costs as recession starts to bite seems a slightly short-sighted strategy, if the desire to attract and maintain customers is an important factor.
There's also implications for the internal Second Life economy too. There's been an upsurge in building and design projects as small businesses and home owners have embraced the potential of new sims. This seems unlikely to continue now.
But I suspect it will fuel the drive towards Open Sims, where such things can be done more cheaply. People who have owned their own private island cheaply will now be looking for a way to continue that experience, without shelling out hugely increased tier. My own feeling in that short term there will be a shrinkage in the landowning community, but soon an explosion of land development in Open Sims as landowners move in looking for a cheaper alternative to offer their customers. Most people will pay a modest tier for a land of their own if the services offered (landscape design, security, stability and, in some cases, themed community) meet their needs - the void sims have proved that. And the inworld businesses that will succeed will be the ones that offer practical support to that.