I don't know anything about Odessa, but I was in Kiev last year and could not believe the amount of development that was going on in the place. It reminded me a lot of Dubai.
And as is the case with Dubai, the same questions arise. When the developments are finished and the speculators want to cash in their chips, who is going to buy them on the secondary market?
Sure, there are quite a few Ukrainians with money, but nowhere near enough to fill all this (already) vacant property.
To us Western Europeans, Ukraine seems like a new and exciting market. To Russians, however, the Black Sea coast is their Costa Del Sol and they have been buying up the prime spots for over a decade already.
Proceed with extreme caution would be my advice on investing in the Ukraine.