LOL, I haven’t even downloaded that version. I’ll get on it.
Ok, thanks to Broken for this pic:
The ‘Velocity’ settings are in the second, “Particle Motion” tab and they are basically the same as they have always been:
Normal: the speed of the particle stream along the normals
Object never been able to get it to work but never needed it either.
Random Randomize the direction and speed of the stream.
Texture Let the texture (*see below) determine the velocity settings of the stream
Damping works like all other damping settings in Blender, ie, it flattens out the speed curve for a soft landing on zero.
Texture Prior to 2.4 you could only use a texture to influence velocity if it was in the eighth texture slot. Now you can set which texture you want to affect the particles by selecting the slot it’s in, to the right of the “Texture” setting I mentioned above, which must have a value set for anything to happen.
In the lower-right corner of the “Particle Motion” tab you can set how the texture properties affect the particles and the tooltips explain all 4 pretty well.
As I said, most of this was already possible before 2.4. What’s new is Weight Painting and Vertex Groups (confusing because, as far as particles are concerned, they are basically the same thing). When you add a Vertex Group the default weight for all verts within that group is 1.000 (full throttle), and the color is Red. The rest, unassigned verts, remains Blue.
As soon as you add a Vertex Group, Weight Painting kicks in and the red areas will emit particles at the velocity of the Velocity settings (all else being equal), while the Blue areas will be suppressed to zero and anything in between at the color value it finds itself. But you could skip the creation of Vertex Groups completely and go straight to Weight Painting.
Set your Particle Effect so it emits from the whole object at about the settings you’ll want. In the 3D window header bar where it says “Object Mode” click the menu and choose “Weight Paint”. In the Buttons Window set F9 for Edit Buttons and choose your Weight and Opacity from the Paint tab. As soon as you start painting you will see the particles arrange themselves according to the colors you paint.