We had a series of polls about hockey's greatest defensemen a few months ago. Lidstrom finished #8 all-time (
http://hfboards.com/showthread.php?t=253940). Most of the regulars here voted in that thread.
My personal opinion is that Lidstrom will probably end up around 9th all-time.
Lidstrom won't crack the top three (Orr, Shore and Harvey). Quite simply, he's never been able to dominate a game, in every aspect, as effectively as that trio. In terms of awards/accolades, Lidstrom would probably need at least 3 more Norris trophies and a couple of Hart trophies to even be considered for the top three, and I doubt that will happen. He almost certainly won't kick Bourque out of fourth place, unless he's a Norris finalist for another decade. (Bourque finished in the top four in Norris voting 19 times). Lidstrom is a slightly better playoff performer (though let's not forget that Bourque was an elite in the postseason despite being on weak teams most of his career and running into the Oilers dynasty). However, Bourque has several more Hart-calibre seasons, has more longevity and was more physical.
Red Kelly and Denis Potvin are 5th and 6th in my mind. Lidstrom lacked Kelly's versatility and Potvin's physical game, but has a fairly similar level of offensive, defensive and postseason performance. Lidstrom
might unseat them with several more Norrises, Harts or Smythes, but there's no guarantee of that.
In 7th spot, you can make an argument for Larry Robinson, Chris Chelios, Brad Park, Pierre Pilotte and Paul Coffey. I think Lidstrom is around that level on the all-time list. Robinson and Park were more complete and played at a somewhat higher level during their primes but Lidstrom compares favorably to the others I mentioned. So #9 all-time is where I think Lidstrom will end up.
(I am considering NHL play only for this post; that's why Fetisov is not on my top 10).