let me preface all this by saying i've just now started into act II, so things may not hold as they are presently.
but.....
i currently use my deathknight as a sword and shield wielding tank. the only bad thing is he seldom gets to 'play'!
he (the deathknight) is my 'lead' character so that i may set my 'hero' to aggressive mode and fire away with arrows. she's so efficient that the DK hardly hits anything (not that he can't, he's just too late!! <img src="/ubbthreads/images/graemlins/biggrin.gif" alt="" />).
here are 2 sequences showing why i use a bow -
sequence 1 7 pic: characters turned away, bow shot, second shot, melee rushing with 2nd earth elemental appearing, still closing, finally trying to engage, 1st EE dead - turn toward 2nd, all dead. no sword hits.
sequence 2 6 pics: firing off screen, damage off screen, more arrow damage, melee rush (notice EE is 3/4 dead already), raising to strike, finally hitting.
between the two sequences we see 3 dead EE and a grand total of 1(!!) melee weapon strike.