Dvorak recently blogged about a particularly nasty outage where various systems went offline due to a problem with MSFT's WGA.
Dvorak's argument seems to be something along the lines of how can you trust someone else's servers which is ridiculous because everyone who has a phone or a connection to the Internet trusts someone else's servers.
I've been around this block a few times and everything old is new again. Today's technology trends are just a reaction to yesterday's pain. Centralized versus distributed computing and licensing versus subscribing to software are the two trends that he is talking about.
With regards to centralized versus distributed computing, it comes down to this. Do you wish to incur the extra scalability costs, that are a part of the TCO for any particular application, all at once or over time? If you chose all at once, then pick a centralized system. If you chose over time, then pick a distributed system.
With regards to licensing versus subscribing, it comes down to this. Do you wish to incur the extra IT costs, that are a part of the TCO for any particular application, all at once or over time? If you chose all at once, then license the software. If you chose over time, then subscribe to the software.
Not that trust isn't an issue. Before subscribing to a service, you should ask yourself whether or not you trust that company to deliver on its promises over time. You should ask that very same question whenever you purchase any product of service from a company, however.
No decision is perfect. There will be advantages and disadvantages any way you go. Just do your best trying to figure out which way is best for you. After that, make your decision and stick with it. Don't look back.