May 21, 2010:
Although many nations (Algeria, Malaysia, Lebanon) are refusing, or retiring, MiG-29s, Syria is eager to get them. That's because Syria is broke, and patron Iran is becoming less generous (because of its own economic problems) with subsidies for military equipment. Thus Russia recently announced that it is selling another 24 (or more) MiG-29s to Syria (which already has about fifty of them). Syria would like to get its existing MiG-29s upgraded, but may not be able to afford that.
Other nations are backing away from MiG-29s because of reliability and durability problems. Several times in the last year, Russia has had MiG-29s grounded because of crashes, and suspicion that there might be some kind of fundamental design flaw. There had been several problems with MiG-29s earlier, although all aircraft were eventually returned to flight status. This has not helped sales, and most export customers prefer the larger Su-27 (and its derivatives like the Su-30).
The MiG-29 entered Russian service in 1983, as the answer to the American F-16. Some 1,600 MiG-29s have been produced so far, with most (about 900) exported. The biggest customer, India, received its first MiG-29s in 1986, with deliveries continuing into the 1990s. The 22 ton aircraft is, indeed, roughly comparable to the F-16, but it depends a lot on which version of either aircraft you are talking about. Then there are the reliability problems. Compared to Western aircraft, like the F-16, the MiG-29 is available for action about two thirds as often.
Syria has not been able to afford to let its pilots spend much time in the air, which reduces wear and tear on the MiG-29s and makes them last longer. Thus the Syrian MiG-29s can expect to provide target practice for more experienced Israeli pilots, flying advanced models of the F-16.