I doubt you can book summer 2010 tickets yet, but it would come down to what you value most: flexibility or price. You can likely do better on some routes if you pre-purchase special offers in advance, but those are not changeable (use it or lose it). However, if your itinerary becomes firm, and the prices for pre-booking point-to-point are significantly cheaper than a pass, then it might be worth it.

Some basics here…. There’s a difference between railpasses and train tickets. You buy a ticket for a specific route (Paris to Frankfurt) or a specific train (Paris to Frankfurt at 14:44 on 30/06/2009). You’d use a railpass instead of buying a ticket for each train for all the trains you take in the countries if covers on the dates it covers.

1. If you choose a railpass then it’s best to buy it in advance for several reasons:
They cost at least 20% more if you buy them in Europe.
You must buy them in person at a eurail aid office and there are only a few of those (although there’s at least one in every capital city)
Not all railpasses are available in Europe and not all passes are available at each office.

2. If you buy an individual train ticket, it may be cheaper to buy it after you get to Europe.
If you buy in advance from any of the rail travel agency websites that sell railpasses you will pay about 1/3 more (plus possibly shipping and handling fees) for a “global” ticket than the regular fare. However, you can sometimes buy tickets on-line from the individual national rail company websites at regular fare and there are sometimes specials available on these sites for specific trains — but you may have to commit (often no refunds or exchanges) to an exact day and time several weeks in advance to take advantage of these specials.

A golden rule observed across Europe is that the sale of reservations starts 60 days before the actual departure. In May 2009, we don’t even know WHICH trains will run in the next timetable season (timetables change in mid-December, the new timetable usually becomes known in October or November). But rail passes MAY be sold further than 60 days in advance as they are not tied down to a particular train.

The German rail site http://reiseauskunft… sells tickets 90 days in advance and some of the specials sell out in the first hours they’re available — the 29 euro specials for Berlin to Munich on August 3 are already sold out for all of the morning trains, but are available for some late afternoon trains.

Tickets on Thalys trains can also be purchased 90 days in advance: www.thalys.com

if I buy an individual train ticket about 2-3 hours before departure, can I still get on the train even if there is no more seat available?

There are a lot of variables in this equation, but most likely “yes.”
1. Some trains require reservations. You can’t board that specific train unless you have a reservation for that specific day and time. If the train is sold out you won’t be able to buy a ticket/reservation for that specific train. If it isn’t sold out, you can usually get a reservation up to one hour before train time, but you may have to wait in a fairly long line. 2 -3 hours should be enough time for a “last minute” purchase, except maybe in Italy.

2. If the train doesn’t require reservations you will be allowed to board the train if you have a ticket. If there are no seats available you will have to stand or sit on your pack at the end of the car. Again, you may have to wait in a fairly long line to buy the ticket, but 2-3 hours should be adequate except maybe in Italy. Many stations have automated ticket kiosks (very helpful in Italy) which will allow you to avoid waiting in line. Some accept cash, others are debit/credit only and there are occasional situations where it might not accept your card. I’d try to purchase any ticket a day in advance if I hadn’t successfully used a kiosk in that country before.

4 months in advance for Eurostar tickets and 60 days in advance for domestic tickets in Italy.
Cheers
Howie