Man... Tough call. As long as Smith (and Tippet) is in PHO, I think SMith's numbers will be solid. That being said, I love Duchene for a rebound/breakout year (returning to his 67/70 point season). I'm a huge Duchene fan and I think his value is at a low right now, making him a difficult move.
As much as I like Smith for solid numbers next year, I'd hate to move Duchene for him. I think you could/should get a better goalie for him (more of a guarantee no matter where he plays) even if it meant packaging another player/pick along with Duchene. Otherwise I'd look to move a different player+ for Smith.
10tm Dynasty Lg - $70M CAP
G A PTS +/- PIM PPP SOG W GAA SV% SO
C: J. Carter, H Sedin, E. Staal
RW: P. Kane, Stewart
LW: Semin, Couture
D: Pietrangelo, Hamhuis, Subban, Carlson
G: Lundqvist, Price
UTIL: Plekanec, Ennis, Perron, D. Brown
D: B. Smith, Morrow
F: Brassard, Williams, Niederreiter, Little, Okposo, Whitney, Nyquist, Kesler
G: S. Mason, Ward
F - Z. Kassian, Spooner, Kuznetsov, Tatar, Teravainen, Stone, Connolly
D - Matt Dumba