While the X1000 does appear a nice machine for Amiga OS4 users there's also other options these days if the price is offputting. There's also MorphOS, which runs on some ppc Macs as well as a few "custom" boards and also runs a decent portion of system friendly (stuff that doesnt hit custom hardware directly (most old floppy based games, etc.)) AmigaOS 680x0 and ppc software "out of the box". In addition to this there's also AROS, which is an open source re-implementation of AmigaOS for industry standard pc hardware, as well as ARM, PPC and 680x0 hardware. Apart from 680x0 hardware however it is only API compatible, in that it takes a recompile for software to run (and 680x0 version is only just now starting to take shape), however there is the option for UAE intergration with x86 AROS, which creates a nice seemless illusion of Amiga software running natively (double click to launch software, AROS menus for 680x0 Amiga software, etc.).
If you've been away for 15 years there's a lot to catch up on. While it's far from a mainstream system these days "amiga" in all it's current day forms (Classic Amiga up to OS3.9, Amiga OS4.x, MOS, AROS, fpga hardware, emulation) is still far from innactive.