yes and no... shadmowmeld gives you the stealth effect but is not the same thing in terms of how you use it. Shadowmeld keeps you invisible just as well as stealth does but its just a "buff" you cant do anything with it except to stay invisible, however you can cast while in shadowmeld UNTIL your casts are completed... so you can mount, mind control, root, etc and not be seen until you have finished your cast. Ive found it extremely useful for Arathi Basin... shadowmeld near the mine, wait for a rogue to start capturing, mindcontrol, he wont see me till hes already controlled... throw him off the cliff, call for backup
