Like everything else, it depends entirely on your viewpoint. There's stuff we will agree on, stuff we wont agree on, and stuff we know nothing about.
In no particular order;
I view Britain as part of Europe, and the emergence of a single E currency as entirely inevitable. Not 'if' but 'when' At the end of the current century there will probably only be three significant currencies in circulation, the Dollar, Yen / Yuan, and the Euro. Note that the Euro will be big, but probably the smallest of the three. Dont like it ? tough....
The most vociferous opponents to the Euro are those in London who make a living charging us commission to change or Pounds into whatever and back again, and the day the last currency-trader can't make a profit can't come soon enough.
Politicians ? dont like 'em, can't trust 'em. Trouble is the Euro-politicians will do at least as good a job of running us as that bunch of XXXX's in Westminster will. For the last few hundred years the sole job of that bunch in Westminster has been screwing the rest of the world (including the rest of Britain) to keep the SE of England in a cushy lifestyle. Just every now and then they take a few years off to do something worthwhile like jump up and down on people that are bent on world domination, but then it's back to business as usual.
The European Constitution ? well, it'll be big, complicated, and the man in the street will know little if anything about it. I predict it will contain exactly as many good points as bads one. I could bang on about the working time directive (junior doctors breath a sigh of relief) or workers rights (trades unionists smile broadens) but I'm sure opponents could quote equally relevant negative points...
I hereby predict that there will be lots of meaningless chat, arguments and political bickering. Either it will all happen in the short term and we will have the constitution and the Euro in the four-year lifetime of the next Parliament, or there will be a hiccup and it'll take one or two more four-year terms before whoever happens to be nominally running the country caves in and joins.
Me? worry? hah. I'm saving small piles of Dollars and Euros even as we speak, and Sean tells me that if you can convince the Canadian government you are a nice person they will let you live out your natural span in a nice isolated bit somewhere. I did note that Geoff and co dont seem to have a higher regard for Canadian politicians than we do for most of the UK ones.
There we go
(ducks, and runs for cover donning flameproof attire)