First off, let me make it clear that I don't know much more about this topic than you do and will only be commenting on what is public knowledge pulling in my experiences as a support engineer.
As you'll no doubt be hearing more of, Oracle seems to be taking an "All or nothing" approach to it's support offerings for Solaris and Sun hardware and with some pretty stringent penalties to try and keep customers going back to Oracle for support (details can be found in this PDF). My understanding is this isn't much different from they way they operate their support pricing for their other Oracle (ie not acquired with Sun) products.
To any previous Sun customer who is also an Oracle customer, this won't come as too much of a surprise and I suspect they may have been expecting this sort of approach to be taken. They may even be happier with this approach. For those who were exclusively Sun customers, this will come as a big surprise and they will not be happy, especially if they've come to rely on Sun's rather relaxed support policies.
The way I see it, this is something Sun should have done years ago when they first started noticing they weren't making the money they wanted to. Sun spent too much time trying to keep everyone happy whilst attempting to make some money from it. Sadly Sun were too good at keeping customers happy "just in case they could make some money off them" than actually making the money. It is well known in and out of Sun that Sun's confusing support levels were open to abuse and were routinely abused by a lot of companies, big and small. This new "all or nothing" approach should take away this confusion, reduce the abuse, and make it very clear to everyone what their level of support is: you either have 24/7 support or you don't. Simple.
This new approach applies to patching too: no more free patches, though the number of free patches has been dropping significantly over the last few years anyway. Those Sun customers who were running Solaris without a support contract are going to be horrified by this and will threaten to switch to RedHat Enterprise Linux only to discover it's pretty much the same thing there: you don't get patches/updates for free for RHEL either. In fact, I believe Sun was the only *NIX OS provider that was giving away free patches for their commercial OS.
Now I'm not privy to the pricing policy for Oracle's Systems/OS support, but given Oracle's reputation for being expensive for support on their database products (remember, you can download Oracle DB for free, you just need to pay for support), I suspect this will be quite expensive and may prove too costly for smaller businesses and these customers may indeed switch to RedHat/Suse/Canonical/whoever. Time will tell.
Of course all is not lost. The most reliable way of patching a machine and ensuring all the patches have been tested and work together is via an OS update. I believe, though I can't promise it'll remain this way, these updates are still and will continue to be free to download and install. Alternatively, there is always the OpenSolaris route and if you want to keep relatively up-to-date, use the /dev repository.
So in summary, I think Oracle's approach is the right one and I'm not just saying this because they pay me. Sun spent too long making very little money at the expense of keeping everyone else happy. Some people won't be happy with this approach, but that's the way Oracle do business. They don't try to keep everyone happy and they're not going to start doing so now they've taken over Sun.