I stand corrected, the “locks” are still there. Following yesterday’s post, I got a comment indicating me the cause of the confusion: Somehow, when I installed the September CTP of Blend 2, my settings were changed (probably by my own doing, in fact), and I unchecked the “Use grid layout mode” checkbox in the “Artboard / Layout” section of the options. This causes the grids to be displayed as a kind of canvas, on which the controls can be positioned in an absolute manner, instead of “fixing” them in a column/row position. Actually, what Blend does is calculate the column, row, columnspan, rowspan and margins to create the positioning which the designer wants to achieve.
I never used the grid’s canvas mode, because I don’t like it. If I want a canvas, I just use a Canvas. Of course, Canvas has other disadvantages, so in fact I don’t really use Canvas anymore either… I love Grids, however, especially the way you can set some of the columns to “Auto” or use the “star-sizing” syntax to specify, for example, that a column should use 33% of the remaining space (that would be Width=”0.33*”).
It is also possible to toggle between Grid layout mode and Canvas layout mode by clicking the small icon on the left-top of the grid (see below). Somehow I overlooked this, and I must thank Christian again for this helpful comment!