SOA - Sounds-like Objects Again
The difficulty with such things is that the vision is always dragged down by the detail, and gaps in the offerings. In SOA, everything sounds good until you realise that there are no services for semantic reconciliation of data from these multiple sources, nor seemingly much in the way of a business inteligence layer. Worse, in order for people to actually build composite applications based on the SOA services, it will require all the current application vendors to meekly open up the guts of their products to allow composite apps to call them. Why exactly would they do this? Of course they will make defensive PR noises about being open, but the goal of application vendors is to sell as much of their own software as possible, not help someone else. Those with the largest entrenched installed base have the most to lose, so expect these vendors to start to offer their own "superior" form of web services, which will allow calls out from their own applications to "legacy" (i.e. anyone but them) applications, but don't hold your breath for services going the other way. After all "legacy" is partly a matter of perspective, rather like freedom fighters and terrorists. If you are SAP then Peoplesoft is legacy, but of you are Oracle then it doesn't look that way.
When looking at industry trends always ask yourself "who is going to make money here?". Well, middleware vendors might, which is why IBM is so keen on the idea. As always, hardware vendors win from anything new and complex, and all that extra network traffic will benefit a further set of vendors. Of course the systems integrators will have a field day actually building those composite apps. So in summary, lots of camps will make money, so expect the hype to continue apace. Whether customers will see much real benefit is another matter.