Appcelerator is already doing well from the current surge of interest in mobile apps, offering an obvious solution to developers endeavouring to support both Apple iOS and Google Android with a single code base. Aptana looks a good acquisition; but the news may not be so welcome to those who rely on Aptana Studio for Adobe AIR; I imagine Appcelerator may see this as a competing platform. Then again, most AIR developers use the Flash IDE or Flash Builder so it is unlikely to have a huge impact even if AIR support is dropped (I do not know what the plans are in this respect).
The server-side technologies like PHP and Ruby are a better fit, since many mobile apps have a server component.
Update: in the webcast about the acquisition, Appcelerator CEO Jeff Haynie said “There’s quite a few questions around Aptana as it relates to Adobe and ColdFusion; I don’t think we can say anything about that.”
The company is expecting to release a joint Aptana Studio/Appcelerator Titanium beta in March 2011. The initial release will not include a visual designer, though this is planned for some future release.