I don't know if this was discussed but I tried it after reading the post about how to remove the sample wallpapers. The sample movie takes up about 1.8Mb and how many times can you see a trailer(no matter how good the quality) Go to the Common Files->RIM->Shared->Loader Files->9530(or the os folder)->Java-> look for the file named net_rim_bb_medialoader_360x480_t.cod.
Change the .cod to anything I used .bak; and there you go load the new os and you will see that the Sample Video is gone. I am running at 41.8 Mb currently.
And if this was posted already just say Thanks and keep it moving.....