I studied Land Arch in UCD and had a great time studying there. I was luck that I had a job to go to when I finished, and having a good bit of pratical experiance gave me a good advantage over my class mates.
During the boom, landscape architects were in high demand as a landscape plan is a usual requirement. Since the boom has burst, planning permission applications have fallen off the page, and therefore the number of planting plans have decreased.
I have been very luck as I have had the chance to do some consultancy work in the UK and this has kept me going over the last few months.
Landscape architecture as a profession is very rewarding when you seen your designs being built, and you feel you have a left your stamp on the world.
If you are seriously considering a career change, don't limit yourself to just design. There is other areas of landscape which you could look in to.
Landscape management is going to be the big thing in future years to come. Turfgrass management is also another area which you might be interseted in, and with all the the golf courses built in the last few years there will always be pleanty of work in this area.
As regards the masters in UCD, I think only one student goes thru the system every 2 or 3 years, so I dont think it is the most organised in the world.