I'll be the strange guys who says absolutely, it CAN be successful IF you understand the market. I understand XCom is going to be ported to the iOS. I don't know what the sales figures were for CivRev, but they probably made money. You'd have really problems arguing that those aren't strategy games.
CivRev is an example of a decent port, I would have liked to see a more complete experience, but it works well enough and has strategy. BGEE(Baldur's gate) is an example of a straight port. It plays like it too.
What I would like to see...
1) Simplify everything
. If it is a rarely used option, pick it for me. If it doesn't provide an 'interesting decision' automate it. Cut down to the core 4X's and automate everything. You can always allow future patches to remove the automation if people scream for it. For instance, let me say that this city is for growth or industry or defense instead of picking buildings. KISS. Keep it simple stupid.
2) Make it an iPad UI. No heavy text menus, everything bigger.
3) Make it discoverable
. Mouse-over doesn't work. So don't rely on all those nifty text tips you have.
4) Old school (Windows 3.1) did everything on mouse-up, you might try to pop a tool-tip up and give people the chance to move their finger if they don't want to do it, but I don't know if that would work.
5) Make it multi-core please. It would probably run 'ok' without it, but faster is always better...
6) Fingers aren't mice, please make the targets big enough for me to hit.
7) Allow me to play for 5 minutes, that means give me a good overview of what's been going on since the last time I picked it up. Bonus points for allowing me to see what my strategy was since I started.
Make it an iPad UI (repeated for emphasis.)
0) Marketing has to start as soon as you have a plan.
1) Consider providing a free version , possibly one that represents a world generated from a specific random seed but with random starting points and opponents. Let people try it first and allow them to upgrade to the full version. Don't cripple it aside form the map selection.
2) Consider offering different unlocks but don't get too greedy and silly about them.