To answer you question of "lockin", it really depends on what portion of WebCT CE, Vista or for that matter Blackboard and Moodle, one is refering to.
One of the features of WebCT CE and Vista along with Moodle is that any of the content files (HTML, PPT, DOC, etc) uploaded into a course file space can be downloaded again as all three support a "File Manager" for managing files including upload
(WebCT CE and Vista even support WebDAV
). However, with Blackboard, once something goes into a course, you can't get it out again, so whatever you do, never delete any locally created files!
Where some of the "lockin" issues come to the front is with content generated within the system such as quizzes and questions. Up until CE 4.x, WebCT only had quiz question export not quiz export. Also, any "content modules" (Moodle "book") could not be exported even though the files contained in the content module could be downloaded. This has all changed with WebCT CE 4.1 and Vista 2.1-3.0 with support for the IMS Content Packaging and IMS QTI specifications through the Content Import/Export features (WebCT's "Open Systems" mantra). For quizzes, there is also Respondus as an intermediary utility. However, with Blackboard, I have yet to find any easy way at the instructor level to export organized content out of a BB course.
For student generated content, that is, discussions, mail, assignments, completed quizzes, etc. that do not count as "content" from an IMS perspective, there still are features for compiling and downloading almost of of this type of "content" for archiving or transfer into another course.
Even though I haven't worked with it too extensively, Blackboard is one of the more difficult systems for retrieving anything, even content that you originally uploaded. This results in far more "lockin" than the WebCT line.
I should point out that SCORM -compliance in Vista should be considered as "Vista accepts SCORM-compliant modules in the same manner as Moodle". Any SCOs produced externally should work in Vista or Moodle. There is no feature to create SCOs in Vista for downloading and using in Moodle.
Actually right now, WebCT is probably more "open systems" than Moodle with WebCT's support of at least three different IMS specifications along with several other industry standards. Right now one can get easily get "locked into" Moodle because of the missing content export functionality based on IMS specifications (and import also.) Note that quiz export just recently appeared in Moodle 1.4.1. Fortunately, with Moodle being "open source", hopefully, the community of Moodle developers can bring Moodle to an "open systems based on open standards" level soon.
Now I'm sure folks are wondering which CMS I prefer. It really depends on all those other factors that go into a pot when deciding on a system. Each has it's strengths and challenges. As a former turfgrass management instructor, I would tell my students during a lecture on mower selection that one doesn't buy 21-inch walk-behind rotary mower for doing football fields (especially Australian Rules Football fields
) or a 100-inch riding mower for doing small home lawns. The same concept also applies to selecting CMSs.