I'm a web developer and I hate SaaS -- hate, hate, hate. My general philosophy is that if I buy an application that doesn't have functionality that requires a connection (e.g. word processor, spreadsheet, solo game versus email, IM, MMORPG), I should be able to take it to my hermit cabin in the woods and run it on a computer powered by a generator without issue. Sure, I won't be able to get the updates, patches, etc. but that's understandable. I really hope this whole model crashes, personally.
As for this specific instance, I'm not as bothered by the DDI being subscription. The vast majority of the offerings on DDI make sense as a subscription. The lone exception is the Character Builder, which does continue to function if you unsubscribe. Also, the DDI provides enough other value that I'll continue to subscribe to it for as long as I play 4e, so it's effectively a non-issue for me.
That said, I'd still strongly prefer that the Character Builder was available as a stand-alone, non-subscription product. I think $30-50 for the application and the PHB, DMG, and MM 1 data would be appropriate. I have to admit that, if the DDI didn't have plenty of subscription-appropriate content, I wouldn't even have tried the CB on principle alone.