the new Canon 600D will probably sell at the same price as the 550D when it first came out.
the tilt LCD will be useful for focusing with live view and for framing especially when object is around zenith. Not more back breaking gymnastics

the 3X to 10 times zoom at 1920 × 1080 pixels, means you can now dispense with barlows when video imaging planets or moon or maybe the sun. Place the DSLR at prime focus with C11 (native focal length 2800mm) and at 10X zoom . Good barlows like Televue are expensive and they don't make them at 10X. Canon's video will probably be at 24p or hopefully at 50/60p
compare with the DMK 41AF02.AS at 1280 x 960 at 15p.
And you have a colour astrophoto and day use camera to boot. It can shoot star trails and DSO and TWAN and your baby's progress as well either in still or video .
Try doing that with the DMK

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Very soon there will be a 'mint' condition 550D available

cheers