Is there something wrong with the old equalizing line 1.e4 e6 2.d3 d5 3.Nd2 Nf6 4.Nf3 Nc6 intending to meet a fianchetto with ...dxe4, ...Bc5, and ...e5 (in some order or other)? Yes, I know that White can delay his fianchetto with 5.c3, but then 5...a5 waiting for the weakening g3 seems reasonable, and 5...Bd6 or even 5...e5 look like playable alternatives.

Full disclosure: I don't regularly play the French (just now and again for exercise), so I may be missing something here.

I agree with MNB.  I prefer 2...c5 and often play my own k-side fianchetto.  In my experience, White seems best prepared to meet 1...e6, d5, c5, even if they've never read Dvoretsky's articles on the KIA.  

Watson also recommends 2...c5 with the idea of g6 and d6, but I don't know if that is a good thing from a practical point of view since many players will also use it.

I'll have to revisit 2..b6, but my first impression is that it lacks bite relative to 2...c5.  Is it a good winning attempt?

Dom - I also moved to the ...b6 system, somehow I never felt safe with my king castled kingside - it surprised me playing through some games that the very old plan with ...0-0-0 was still playable.

After reading one J.Watson "Play the French" book I tried one system with Bd6-Nc6-Nge7 but nowadays I am back in following b6 system where I get more and more experience vs the KIA.

Here is one game last week in Nice tournament (sorry next time I will put PGN file attachement here):
Armas Lena 1796 Naujac - Laurain Dominique 2012 Tournefeuille
1.e4 e6 2.d3 { start of KIA } d5 3.Qe2 { Nd2 is more common, now game comes back in Chigorin variation } Be7 4.g3 b6 { one can argue about this move is slower than b5 in some lines, but I like this all-purposes move } 5.Bg2 Bb7 { dxe4 opening the a6-f1 diagonal can be another plan but I am not sure it is better } 6. Nf3 { f4 can be another idea but with some main disadvantage: limiting bishop c1 scope } Nf6 7.Nd2 { admitting now a loss of tempo because Chigorin line is more for a quick development and sometimes long castle } c5 8.oo Nc6 { as you see, Black is no in hurry to castle short, and now White as some problem on the c file  } 9.e5 { White keeped flexible center as long as possible but now must play this move which usually gives a kingside attack but at the price of a weak e5 pawn } Nd7 10.c3 { trying to build the dreamed strong center with c3-d4-e5 } g5! { the g5 counternstrike pattern as given by J.Watson in last update for other variation...basic idea is attacking one defender of e5 pawn, the f3 square knight } 11.d4 h5 { before playing g4, protect the g4 square } 12.Nb3 g4 13.Ne1 a5 14.a4 Ba6 15.Qd1 Bc4 16.Be3 Bxf1 17.Bxf1 Bg5 18.Bb5 Rc8 19.Bxg5 Qxg5 20.Bf1 c4 21.Nc1 h4 22.b3 hxg3 23.fxg3? Qxe3+ 24.Kg2 Rxh2+ { a classical tactical blow and  h file attack } 25.Kxh2 Qf2+ 26.Kh1 Qxf1+ 27.Kh2 Ke7 and White resigns

My favourite is 2...c5. Not only does this fit in about all French setups, sometimes it is nice to play the Sicilian ...d6 instead of ...d5.