As I understand it the Mic input on the XM1 is a stereo mini jack. Canon do make an adaptor that is powered from the shoe that gives you two mono XLR sockets both of which have phantom power available for powering pro condenser mics.

Depending on the mic/mics you want to use you may or may not need this. If you want to use condenser mics that require 48V phantom power (as MOST pro mics do) then you will need one) If however you can manage with a dynamic mic or a condenser that is powered by an internal battery, then the right kind of adapter is all that is required.

Mics that fall into the latter category that come to mind are the ubiquitous Shure SM58 vocal mic, (dynamic) the Rode videomic (internally powered condenser) the shure would require an XLR - Mini jack cable, the Rode already is suitable for mini-jack operation.

There are a number of consumer/prosumer mics that are designed for camcorder use without the need for an XLR adapter. The Canon DM50 would work with the XM1, it is a dual mode shotgun/stereo wide field mic, that powers off the canon hot-shoe, the Sennheiser MKE400 is a little new shotgun designed for small higher end consumer camcorders. I just got me an Audio Technica ATR25 stereo mic, which is silly cheap money for what is actually quite a good mic. They also do the ATR55 which is s shotgun version.

I really like some of the Bayer Dynamic stuff - the MCE 86 II S is a battery powered shotgun with a great spec, but it's not cheap.

But if you already have some high-end phantom powered mics around the only solution really is an adapter, the Canon MA300 should be compatible (but check with the dealer), alternatively look at the BeachTec range.

If you don't need a field solution and you are going to be working in a studio situation, you could look at a small mixer from the likes of Mackie, 402 VZL3, (about £90) all of which will have good preamps and phantom power, and use the mixer output to drive the line-in on your camcorder