could be good, could be bad
my company uses SAP and we use Ariba On-Demand. Making the two fit together has sometimes been difficult. It will be interesting to see exactly how much leash Ariba gets and how long they remain an "independent business unit".
Our biggest problem is that Ariba handles indirect spend (widgets) very well, but direct spend (raw materials) is simply awful in Ariba and nigh impossible without frightfully expensive add-ons. Ariba bought out Quadrem, which was supposed to resolve that problem but the full integration was going to take up to three years. Now, with the SAP buyout, that water could become even murkier OR much clearer. Given SAP's penetration into manufacturing firms like my employer, they may "suggest" Ariba move faster on the Quadrem integration. That's my HOPE, anyway.