The Year 2000 rollover, it appears after all, will be rather smooth. Despite fears of widespread computer shutdowns or malfunctions or millennium-related terrorism in Israel or elsewhere, the year 2000 arrived amid tremendous fanfare, but few technical difficulties. While some minor problems popped up in various spots around the globe, Y2K seems to have arrived with fewer computer problems than even the most sanguine analysts predicted. The acid test, of course, is the next few days, as computer networks that were shut down or quiet for the holiday weekend get a full workout. Initial indications are positive, as stock markets in Asia and Europe successfully opened up and experienced brisk trading. While officials and analysts warn that the danger for serious problems has not passed entirely, most admit that the risk is very low at this point. More likely is a series of small glitches and nuisances that will be worked out over the coming weeks and months.