Best line for White I found after Morozevich move 7..Be7!? Ivanchuk-Morozevich,Memorial Donner 1996 (Pavloc,Europe Echecs 1997) is indeed a mix Be2-Qd2, kind of wait&see strategy for kingside or queenside castling.
8.Be2 (better to do this move first, trying to transpose to: 8.Qd2 a6 9.Be2!? ; if White plays Qd2 first then Black must avoid a6 where White has 9.Be2!? and 9.dxc5! Nxc5 10.Nd4 oo 11.Bd3 with small advantage to White or 9.ooo b5 10.dxc5 Nxc5 11.Qf2 ; my twin brother played as White 8.Qd2 oo 9.ooo a6 10.dxc5 Bxc5 11.Nd4 Nxd4 12.Bxd4 b5 13.Qe3 Bxd4 14.Qxd4 Qc7 15.Bd3 Bb7 16.Rhe1 Nc5 17.f5 exf5 18.Bxf5 Rfe8 and an easy draw for White at the end Laurain G,Nogueiras, COQ 2003) and now
A) 8...a6 9.oo (now better to castle kingside) oo 10.Qd2 b5 11.Nd1 (htreatening c3 and a strong pawn center) cxd4 (11...b4 12.c3 a5 13.Kh1 Ba6 14.Bxa6 Rxa6 15.Rc1 bxc3 16.Nxc3 c4 17.f5 Nb4 18.Ne1 Nc6 19.Qe2 Bg5 20.Rd1 Bxe3 21.Qxe3 f6 22.fxe6 fxe5 23.Nf3 exd4 24.Nxd4 Rxf1+ 25.Rxf1 Nxd4 26.e7 Qe8 27.Qxd4 Qxe7 28.Nxd5 Qe2 29.Kg1 Re6 30.Qa7 Kf8 31.Qf7+ Voitsekhovski-Vitinik,Sochi 2007) 12.Nxd4 Nxd4 13.Bxd4 Nb8 14.Ne3 Nc6 15.c3 and small advantage to White
B) 8...oo 9.Qd2 (9.oo f6!?) cxd4 (9...a6 Timofeev-Wang Hao,Taiyuan 2006 10.oo transposes to A)) 10.Nxd4 Nxd4 11.Bxd4 Nb8 (same strategy as above without a6) 12.oo and a very small advantage for White Timman-Hort,Linares 1983 (Tiemann)
of course White may be disappointed with "the small advantage" assessment, and maybe has to try more risky play for a win like in: 8.g3!? line Nijboer-Ni Hua, olympiads Turin 2006. Look at game on
www.chessgames.com another line for White is: 8.Qd2 cxd4 (8..a6 or 8..oo see above) 9.Nxd4 oo 10.ooo Bb4 11.Nb3 (now position has transpoed in Nijboer line, analyse in Khalifman book) a6 12.Bd3 (12.a3?! Be7) b5 and so on (see other threads in French forum)